mdbx: update ChangeLog.

mdbx++: add missing std::hash<mdbx::buffer<>>.
mdbx-windows: use timeouts instead of retries for file locking.
2025-12-16 17:12:23 +08:00 · 2025-11-12 18:10:35 +03:00 · 2025-11-12 17:54:57 +03:00 · 2025-11-12 17:54:57 +03:00 · 2025-11-12 17:54:40 +03:00 · 2025-11-10 21:38:06 +03:00
50 changed files with 1305 additions and 846 deletions
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -335,19 +335,6 @@ if(NOT APPLE
  endif()
 endif()

-check_function_exists(pow NOT_NEED_LIBM)
-if(NOT_NEED_LIBM)
-  set(LIB_MATH "")
-else()
-  set(CMAKE_REQUIRED_LIBRARIES m)
-  check_function_exists(pow HAVE_LIBM)
-  if(HAVE_LIBM)
-    set(LIB_MATH m)
-  else()
-    message(FATAL_ERROR "No libm found for math support")
-  endif()
-endif()
-
 if(SUBPROJECT)
  if(NOT DEFINED BUILD_SHARED_LIBS)
    option(BUILD_SHARED_LIBS "Build shared libraries (DLLs)" OFF)
@@ -705,6 +692,8 @@ mark_as_advanced(MDBX_ENABLE_PROFGC)
 add_option(MDBX ENABLE_DBI_SPARSE
           "Support for sparse sets of DBI handles to reduce overhead when starting and processing transactions" ON)
 add_option(MDBX ENABLE_DBI_LOCKFREE "Support for deferred releasing and a lockfree path to quickly open DBI handles" ON)
+add_option(MDBX USE_FALLOCATE "Using posix_fallocate() or fcntl(F_PREALLOCATE) on OSX" AUTO)
+mark_as_advanced(MDBX_USE_FALLOCATE)

 if(NOT MDBX_AMALGAMATED_SOURCE)
  if(CMAKE_CONFIGURATION_TYPES OR CMAKE_BUILD_TYPE_UPPERCASE STREQUAL "DEBUG")
@@ -1034,10 +1023,6 @@ if(MDBX_BUILD_TOOLS)
    target_setup_options(mdbx_${TOOL})
    target_link_libraries(mdbx_${TOOL} ${TOOL_MDBX_LIB})
  endforeach()
-  if(LIB_MATH)
-    target_link_libraries(mdbx_chk ${LIB_MATH})
-    target_link_libraries(mdbx_stat ${LIB_MATH})
-  endif()
 endif()

 # ######################################################################################################################
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -9,7 +9,7 @@ Please use the `stable` branch or the latest release for production environment
 Donations are welcome to ETH `0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A`.
 Всё будет хорошо!

-## v0.14.2 в активной разработке без конкретизации даты выпуска
+## v0.14.2 в разработке без конкретизации даты выпуска

 Продолжение развития нового куста/линейки версий с добавлением функционала, расширением API и внутренними переработками.

@@ -17,6 +17,7 @@ Donations are welcome to ETH `0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A`.

 - [Erigon](https://erigon.tech/) за спонсорство.
 - [Артёму Воротникову](https://github.com/vorot93) за сообщение об ошибках и тестировании [призязок для Rust](https://github.com/vorot93/libmdbx-rs).
+ - [Stefan de Konink](https://github.com/skinkie) for fixing [Python bindings](https://github.com/wtdcode/mdbx-py) and documentation improvement.

 Новое:

@@ -35,6 +36,15 @@ Donations are welcome to ETH `0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A`.
 - В API копирования БД добавлена опция `MDBX_CP_OVERWRITE` (перезапись целевого файла),
   а в утилиту `mdbx_copy` аналогичная по смыслу опция командной строки `-f` .

+ - Поддержка Harmony OS (OHOS).
+
+ - Операции с плавающей точкой больше не используются как внутри библиотеки, так и в утилитах, а из сценариев сборки удалено связывание c `libm`.
+
+ - Обеспечена возможность установки отладочных опций `MDBX_DBG_ASSERT`, `MDBX_DBG_AUDIT` и других, через переменные среды окружения.
+   Но соответствующие отладочные возможности по-прежнему должны быть активированы во время сборки.
+
+ - Расширен и переработан состав информации формируемой функцией `mdbx_chk_env()` и выводимой утилитой `mdbx_chk`.
+
 Исправления:

 - Устранена критическая ошибка в функционале `mdbx_env_resurrect_after_fork()` при использовании SysV-семафоров.
@@ -63,20 +73,41 @@ Donations are welcome to ETH `0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A`.
 - Устранено получение неожиданного `SIGBUS` из-за отложенного/ленивого выделение места в заполненной файловой системе после приращения файла БД.
   Более подробное пояснение в комментарии коммита [`2a7f460345edbeb26a51782cbe6af3c55254ae77`](https://gitflic.ru/project/erthink/libmdbx/commit/2a7f460345edbeb26a51782cbe6af3c55254ae77).

+ - Исправлена assert-проверка в пути сканирования битовой карты DBI-дексрипторов приводившая к редким падениям 32-битных отладочных сборок.
+
+ - Переделан поиск утилит `lib.exe` и `dlltool.exe` при сборке посредством CMake на Windows.
+
+ - Устранено падение при выполнении Thread-Local-Storage конструкторов при выгрузке библиотеки и наличия экземпляров env, инициализация которых не была завершена.
+
+ - В C++ API добавлена упущенная специализация шаблона `std::hash<mdbx::buffer<...>>`.
+
 Изменение поведения:

 - Вновь включена/разрешена на старых ядрах Linux, начиная с версии 3.16, так как
   сейчас уже нет причин отказываться от работы на 3.16 поддерживая при этом ядра 4.x,
   и еще есть проекты (Isar, Isar-Community, Hive) которым требуется такая поддержка.

+ - Изменено значение по-умолчанию порога слияния страниц с 25% до 33%.
+
+ - Ошибка `MDBX_WANNA_RECOVERY` при открытии БД в режиме только-чтение теперь возвращается если размер БД не кратен размеру системной страницы,
+   но игнорируется не кратность размеру блока выделения виртуальной памяти. Этим устраняется регресс, проявившейся вследствие изменения поведения
+   после задействования системного вызова `fallocate()` для предотвращения `SIGBUS` после приращения файла БД в заполненной файловой системе.
+
+ - Для уменьшения вероятности неожиданных ошибок, вследствие переходных процессах и отложенной обработки в ядре ОС при конкурентном закрытии и
+   открытии БД разными процессами, втрое увеличено количество повторных попыток захвата блокировок. Предположительно это также решит проблему
+   неожиданных ошибок `EAGAIN` (11) на Android при рестарте приложений и открытия БД сразу после закрытия.
+
+ - По-умолчанию сборка для Windows теперь выполняется с использованием SDK уровня Windows 10, а не Windows 7.
+
+ - Изменён размер и состав структуры `MDBX_envinfo`, а функция `mdbx_env_info_ex()` больше не поддерживает старые варианты.
+   Этим нарушена совместимость ABI со старыми версиями библиотеке, но сохранена совместимость API на уровне исходного кода.
+
 Прочие доработки:

 - Доработана логика отказа от использования OFD-блокировок на POSIX-платформах.
   Теперь кроме `EINVAL` учитываются дополнительные коды ошибок (`ENOSYS`, `ENOIMPL`, `ENOTSUP`, `ENOSUPP`, `EOPNOTSUPP`),
   что позволит работать собранной библиотеке в некоторых случаях, когда актуальное ядро/контейнер/эмулятор не поддерживает требуемых системных вызовов.

- - Изменено значение по-умолчанию порога слияния страниц с 25% до 33%.
-
 - Тесты дополнены сценариями для проверки добавленных возможностей, выявленных регрессов и ошибок.

 - В тестовый фреймворк добавлена поддержка опции --numa # для привязки стохастического теста к NUMA-узлу,
@@ -87,6 +118,16 @@ Donations are welcome to ETH `0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A`.

 - В функционал проверки целостности БД и утилиту mdbx_chk добавлен вывод гистограммы заполнения страниц образующих структуру дерева и участвующих в операциях разделения/слияния/перебалансировки.

+ - Для Android добавлен обход (workaround) для уменьшения вероятности системной ошибки `EAGAIN` возникающей
+   из-за нехватки системных ресурсов и переходных процессов при закрытии и быстром повтороном открытии БД.
+
+ - Для Linux добавлено предотвращение проявления ошибки в реализации fast_commit файловой системы Ext4.
+
+ - В отладочные сборки на Windows при срабатывании assert-проверок добавлена поддержка вариантов "Пропустить" и "Повторить".
+
+ - В используемых на платформе Windows файловых блокировках задействованы ожидания с таймаутами,
+   что теоретически должно снизить вероятность возникновения ошибок `ERROR_LOCK_VIOLATION` (`33`) при открытии БД в конкуррентных сценариях.
+

 --------------------------------------------------------------------------------

@@ -372,6 +413,69 @@ Donations are welcome to ETH `0xD104d8f8B2dC312aaD74899F83EBf3EEBDC1EA3A`.
 ********************************************************************************


+## v0.13.9 "ИС-2" (IS-2) от 2025-10-31
+
+Поддерживающий выпуск стабильной ветки с исправлением обнаруженных ошибок и устранением недочётов.
+Выпуск назван в память о cамом мощном тяжелом советском танке ["ИС-2"](https://ru.ruwiki.ru/wiki/ИС-2), который был принят на вооружение
+31 октября 1943 года в разгар Великой Отечественной Войны и долгое время оставался одной из сильнейших машин мира в категории по массе 40—50 тонн.
+
+Благодарности:
+
+ - [Erigon](https://erigon.tech/) за спонсорство.
+
+Исправления:
+
+ - Исправлена assert-проверка в пути сканирования битовой карты DBI-дескрипторов приводившая к редким падениям 32-битных отладочных сборок.
+
+ - Переделан поиск утилит `lib.exe` и `dlltool.exe` при сборке посредством CMake на Windows.
+
+ - Устранён регресс проявлявшийся увеличением (не-уменьшением) размера БД, после добавления использования `fallocate()`
+   ради предотвращения SIGBUS при нехватке места в файловой системе где расположена БД.
+
+ - Устранена опечатка в тестовом скрипте `test/battery-tmux.sh` приводящая к созданию мусорного файла с именем `-`.
+
+ - Удалено лишнее/ненужное использование макроса `MDBX_INTERNAL` оставшееся после рефакторинга.
+
+ - Для Android добавлен обход (workaround) для уменьшения вероятности системной ошибки `EAGAIN` возникающей
+   из-за нехватки системных ресурсов и переходных процессов при закрытии и быстром повторном открытии БД.
+
+Прочие доработки:
+
+ - Поддержка Harmony OS (OHOS).
+
+
+--------------------------------------------------------------------------------
+
+
+## v0.13.8 "Всеобуч" (v`seabooch) от 2025-08-31
+
+Поддерживающий выпуск стабильной ветки с исправлением обнаруженных ошибок и устранением недочётов,
+в день 100 летнего юбилея Постановления Всероссийского центрального исполнительного комитета о всеобщем бесплатном начальном образовании.
+
+Благодарности:
+
+ - [Erigon](https://erigon.tech/) за спонсорство.
+
+Исправления:
+
+ - Устранена возможность получения неожиданного `SIGBUS` из-за отложенного/ленивого выделение места в заполненной файловой системе после приращения файла БД.
+   Более подробное пояснение в комментарии коммита [`2930b304dc674bbccd188b7ce7c3f83755ef706e`](https://gitflic.ru/project/erthink/libmdbx/commit/2930b304dc674bbccd188b7ce7c3f83755ef706e).
+
+Изменение поведения:
+
+ - Вновь включена/разрешена на старых ядрах Linux, начиная с версии 3.16, так как
+   сейчас уже нет причин отказываться от работы на 3.16 поддерживая при этом ядра 4.x,
+   и еще есть проекты (Isar, Isar-Community, Hive) которым требуется такая поддержка.
+
+ - Ошибка `MDBX_WANNA_RECOVERY` при открытии БД в режиме только-чтение теперь возвращается если размер БД не кратен размеру системной страницы,
+   но игнорируется не кратность размеру блока выделения виртуальной памяти.
+   Этим устраняется регресс, проявившейся вследствие изменения поведения после задействования
+   системного вызова `fallocate()` для предотвращения `SIGBUS` после приращения файла БД в заполненной файловой системе.
+
+
+--------------------------------------------------------------------------------
+
+
 ## v0.13.7 "Дружба" (Friendship) от 2025-07-30.

 Поддерживающий выпуск стабильной ветки с исправлением обнаруженных ошибок и устранением недочётов,
--- a/13
+++ b/13
@@ -106,11 +106,12 @@ endef
 define uname2ldflags
  case "$(UNAME)" in
    CYGWIN*|MINGW*|MSYS*|Windows*)
-      echo '-Wl,--gc-sections,-O1';
+      echo '-Wl,--gc-sections,-O1,--as-needed';
      ;;
    *)
      $(LD) --help 2>/dev/null | grep -q -- --gc-sections && echo '-Wl,--gc-sections,-z,relro,-O1';
      $(LD) --help 2>/dev/null | grep -q -- -dead_strip && echo '-Wl,-dead_strip';
+      $(LD) --help 2>/dev/null | grep -q -- --as-needed && echo '-Wl,--as-needed';
      ;;
  esac
 endef
@@ -119,16 +120,16 @@ endef
 define uname2libs
  case "$(UNAME)" in
    CYGWIN*|MINGW*|MSYS*|Windows*)
-      echo '-lm -lntdll -lwinmm';
+      echo '-lntdll -lwinmm';
      ;;
    *SunOS*|*Solaris*)
-      echo '-lm -lkstat -lrt';
+      echo '-lkstat -lrt';
      ;;
    *Darwin*|OpenBSD*)
-      echo '-lm';
+      echo '';
      ;;
    *)
-      echo '-lm -lrt';
+      echo '-lrt';
      ;;
  esac
 endef
@@ -561,7 +562,7 @@ $(foreach file,$(TOOLS),$(eval $(call tool-rule,$(file))))

 mdbx_test: $(TEST_OBJ) libmdbx.$(SO_SUFFIX)
 	@echo '  LD $@'
-	$(QUIET)$(CXX) $(CXXFLAGS) $(TEST_OBJ) -Wl,-rpath . -L . -l mdbx $(EXE_LDFLAGS) $(LIBS) -o $@
+	$(QUIET)$(CXX) $(CXXFLAGS) $(TEST_OBJ) -Wl,-rpath . -L . -l mdbx $(EXE_LDFLAGS) $(LIBS) -lm -o $@

 $(MDBX_GIT_DIR)/HEAD $(MDBX_GIT_DIR)/index $(MDBX_GIT_DIR)/refs/tags:
 	@echo '*** ' >&2
--- a/TODO.md
+++ b/TODO.md
@@ -1,6 +1,9 @@
+
 TODO
 ----

+ - add optional page-get and operation statistics for cursors.
+ - split ASSERT() to CHECK{0,1,2,3} and basal `assert()`.
 - [SWIG](https://www.swig.org/).
 - Параллельная lto-сборка с устранением предупреждений.
 - Интеграция c DTrace и аналогами.
@@ -16,9 +19,15 @@ TODO
 - [Support MessagePack for Keys & Values](https://libmdbx.dqdkfa.ru/dead-github/issues/115).
 - Packages for [Astra Linux](https://astralinux.ru/), [ALT Linux](https://www.altlinux.org/), [ROSA Linux](https://www.rosalinux.ru/), etc.

+In development
+--------------
+ - get-cached API.
+ - digging/refactoring/optimizing page splitting and tree rebalance.
+
 Done
 ----

+ - HarmonyOS support.
 - Ранняя/не-отложенная очистка GC.
 - Рефакторинг gc-get/gc-put c переходом на "интервальные" списки.
 - [Engage new terminology](https://libmdbx.dqdkfa.ru/dead-github/issues/137).
--- a/conanfile.py
+++ b/conanfile.py
@@ -82,6 +82,7 @@ class libmdbx(ConanFile):
        'mdbx.use_mincore': ['Auto', True, False],
        'mdbx.use_ofdlocks': ['Auto', True, False],
        'mdbx.use_sendfile': ['Auto', True, False],
+        'mdbx.use_fallocate': ['Auto', True, False],
        'mdbx.without_msvc_crt': ['Default', True, False],
        'shared': [True, False],
    }
@@ -113,6 +114,7 @@ class libmdbx(ConanFile):
        'mdbx.use_mincore': 'Auto',
        'mdbx.use_ofdlocks': 'Auto',
        'mdbx.use_sendfile': 'Auto',
+        'mdbx.use_fallocate': 'Auto',
        'mdbx.without_msvc_crt': 'Default',
        'shared': True,
    }
@@ -143,7 +145,8 @@ class libmdbx(ConanFile):
        'mdbx.use_copyfilerange': 'Advanced: Use `copy_file_range()` syscall. ',
        'mdbx.use_mincore': "Use Unix' `mincore()` to determine whether database pages are resident in memory. ",
        'mdbx.use_ofdlocks': 'Advanced: Use POSIX OFD-locks. ',
-        'mdbx.use_sendfile': 'Advancedc: Use `sendfile()` syscall. ',
+        'mdbx.use_sendfile': 'Advanced: Use `sendfile()` syscall. ',
+        'mdbx.use_fallocate': 'Advanced: Use posix_fallocate() or fcntl(F_PREALLOCATE) on OSX. ',
        'mdbx.without_msvc_crt': 'Avoid dependence from MSVC CRT and use ntdll.dll instead. ',
    }

@@ -160,6 +163,7 @@ class libmdbx(ConanFile):
            self.options.rm_safe('mdbx.mmap_incoherent_file_write')
            self.options.rm_safe('mdbx.use_mincore')
            self.options.rm_safe('mdbx.use_ofdlocks')
+            self.options.rm_safe('mdbx.use_fallocate')
        else:
            self.options.rm_safe('mdbx.without_msvc_crt')
        if is_apple_os(self):
--- a/mdbx.h
+++ b/mdbx.h
@@ -837,7 +837,9 @@ enum MDBX_constants {

 /** Log level
 * \note Levels detailed than (great than) \ref MDBX_LOG_NOTICE
- * requires build libmdbx with \ref MDBX_DEBUG option. */
+ * requires build libmdbx with \ref MDBX_DEBUG option.
+ *
+ * \see mdbx_setup_debug() \see MDBX_log_level_t */
 typedef enum MDBX_log_level {
  /** Critical conditions, i.e. assertion failures.
   * \note libmdbx always produces such messages regardless
@@ -894,24 +896,26 @@ typedef enum MDBX_log_level {
 *
 * \details `MDBX_DBG_DUMP` and `MDBX_DBG_LEGACY_MULTIOPEN` always have an
 * effect, but `MDBX_DBG_ASSERT`, `MDBX_DBG_AUDIT` and `MDBX_DBG_JITTER` only if
- * libmdbx built with \ref MDBX_DEBUG. */
+ * libmdbx built with \ref MDBX_DEBUG.
+ *
+ * \see mdbx_setup_debug() \see MDBX_debug_flags_t */
 typedef enum MDBX_debug_flags {
  MDBX_DBG_NONE = 0,

-  /** Enable assertion checks.
+  /** Enables assertion checks.
   * \note Always enabled for builds with `MDBX_FORCE_ASSERTIONS` option,
   * otherwise requires build with \ref MDBX_DEBUG > 0 */
  MDBX_DBG_ASSERT = 1,

-  /** Enable pages usage audit at commit transactions.
+  /** Enables pages usage audit at commit transactions.
   * \note Requires build with \ref MDBX_DEBUG > 0 */
  MDBX_DBG_AUDIT = 2,

-  /** Enable small random delays in critical points.
+  /** Enables small random delays in critical points.
   * \note Requires build with \ref MDBX_DEBUG > 0 */
  MDBX_DBG_JITTER = 4,

-  /** Include or not meta-pages in coredump files.
+  /** Controls including of a database(s) meta-pages in coredump files.
   * \note May affect performance in \ref MDBX_WRITEMAP mode */
  MDBX_DBG_DUMP = 8,

@@ -921,9 +925,8 @@ typedef enum MDBX_debug_flags {
  /** Allow read and write transactions overlapping for the same thread. */
  MDBX_DBG_LEGACY_OVERLAP = 32,

-  /** Don't auto-upgrade format signature.
-   * \note However a new write transactions will use and store
-   * the last signature regardless this flag */
+  /** Disables automatic updating of the database format signature, i.e. upgrade database format on a media.
+   * \note Nonetheless a new write transactions will use and store the last signature regardless this flag */
  MDBX_DBG_DONT_UPGRADE = 64,

 #ifdef ENABLE_UBSAN
@@ -958,7 +961,9 @@ typedef void MDBX_debug_func(MDBX_log_level_t loglevel, const char *function, in

 /** \brief Setup global log-level, debug options and debug logger.
 * \returns The previously `debug_flags` in the 0-15 bits
- *          and `log_level` in the 16-31 bits. */
+ *          and `log_level` in the 16-31 bits.
+ *
+ * \see MDBX_log_level_t \see MDBX_debug_flags_t */
 LIBMDBX_API int mdbx_setup_debug(MDBX_log_level_t log_level, MDBX_debug_flags_t debug_flags, MDBX_debug_func *logger);

 typedef void MDBX_debug_func_nofmt(MDBX_log_level_t loglevel, const char *function, int line, const char *msg,
@@ -1007,7 +1012,10 @@ MDBX_NORETURN LIBMDBX_API void mdbx_panic(const char *fmt, ...) MDBX_PRINTF_ARGS

 /** \brief Panics with asserton failed message and causes abnormal process
 * termination. */
-MDBX_NORETURN LIBMDBX_API void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *func, unsigned line);
+#if !((defined(_WIN32) || defined(_WIN64)) && !MDBX_WITHOUT_MSVC_CRT)
+MDBX_NORETURN
+#endif /* MDBX_WITHOUT_MSVC_CRT */
+LIBMDBX_API void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *func, unsigned line);
 /** end of c_debug @} */

 /** \brief Environment flags
@@ -1904,8 +1912,7 @@ typedef enum MDBX_error {
   *  - The table was dropped and recreated with different flags. */
  MDBX_INCOMPATIBLE = -30784,

-  /** Invalid reuse of reader locktable slot,
-   * e.g. read-transaction already run for current thread */
+  /** Reader locktable slot was unexpectly reused or cleared by an enemy thread */
  MDBX_BAD_RSLOT = -30783,

  /** Transaction is not valid for requested operation,
@@ -2810,17 +2817,20 @@ struct MDBX_envinfo {
    uint64_t shrink;  /**< Shrink threshold for datafile */
    uint64_t grow;    /**< Growth step for datafile */
  } mi_geo;
-  uint64_t mi_mapsize;                  /**< Size of the data memory map */
+  uint64_t mi_mapsize;                  /**< Size of the database memory map */
+  uint64_t mi_dxb_fsize;                /**< Current database file size */
+  uint64_t mi_dxb_fallocated;           /**< Space allocated for the database file in a filesystem */
  uint64_t mi_last_pgno;                /**< Number of the last used page */
  uint64_t mi_recent_txnid;             /**< ID of the last committed transaction */
  uint64_t mi_latter_reader_txnid;      /**< ID of the last reader transaction */
-  uint64_t mi_self_latter_reader_txnid; /**< ID of the last reader transaction
-                                           of caller process */
+  uint64_t mi_self_latter_reader_txnid; /**< ID of the last reader transaction of this/current process */
  uint64_t mi_meta_txnid[3], mi_meta_sign[3];
  uint32_t mi_maxreaders;   /**< Total reader slots in the environment */
  uint32_t mi_numreaders;   /**< Max reader slots used in the environment */
  uint32_t mi_dxb_pagesize; /**< Database pagesize */
  uint32_t mi_sys_pagesize; /**< System pagesize */
+  uint32_t mi_sys_upcblk;   /**< System "Unified Page Cache" block size */
+  uint32_t mi_sys_ioblk;    /**< Filesystem I/O block size */

  /** \brief A mostly unique ID that is regenerated on each boot.

@@ -4562,6 +4572,10 @@ typedef int(MDBX_cmp_func)(const MDBX_val *a, const MDBX_val *b) MDBX_CXX17_NOEX
 * \param [out] dbi     Address where the new \ref MDBX_dbi handle
 *                      will be stored.
 *
+ * The name in \ref mdbx_dbi_open() is a null terminated string. While
+ * \ref mdbx_dbi_open2() supports arbitrary length keys which are not
+ * truncated, for example to support a fixed width integer type.
+ *
 * For \ref mdbx_dbi_open_ex() additional arguments allow you to set custom
 * comparison functions for keys and values (for multimaps).
 * \see avoid_custom_comparators
@@ -4594,6 +4608,8 @@ LIBMDBX_API int mdbx_dbi_open2(MDBX_txn *txn, const MDBX_val *name, MDBX_db_flag
 * \param [in] name   The name of the table to open. If only a single
 *                    table is needed in the environment,
 *                    this value may be NULL.
+ *                    The name in \ref mdbx_dbi_open_ex() is null terminated,
+ *                    while \ref mdbx_dbi_open_ex2() supports an arbitrary length.
 * \param [in] flags  Special options for this table.
 * \param [in] keycmp  Optional custom key comparison function for a table.
 * \param [in] datacmp Optional custom data comparison function for a table.
@@ -6534,17 +6550,17 @@ typedef struct MDBX_chk_table {

  size_t payload_bytes, lost_bytes;
  struct {
-    size_t all, empty, other;
+    size_t all, empty, broken;
    size_t branch, leaf;
    size_t nested_branch, nested_leaf, nested_subleaf;
  } pages;
  struct {
    /// Tree deep histogram
-    struct MDBX_chk_histogram deep;
+    struct MDBX_chk_histogram height;
    /// Histogram of large/overflow pages length
    struct MDBX_chk_histogram large_pages;
    /// Histogram of nested trees height, span length for GC
-    struct MDBX_chk_histogram nested_tree;
+    struct MDBX_chk_histogram nested_height;
    /// Keys length histogram
    struct MDBX_chk_histogram key_len;
    /// Values length histogram
@@ -6552,9 +6568,9 @@ typedef struct MDBX_chk_table {
    /// Number of multi-values (aka duplicates) histogram
    struct MDBX_chk_histogram multival;
    /// Histogram of branch and leaf pages filling in percents
-    struct MDBX_chk_histogram tree_filling;
+    struct MDBX_chk_histogram tree_density;
    /// Histogram of nested tree(s) branch and leaf pages filling in percents
-    struct MDBX_chk_histogram nested_tree_filling;
+    struct MDBX_chk_histogram large_or_nested_density;
  } histogram;
 } MDBX_chk_table_t;

@@ -6661,6 +6677,11 @@ LIBMDBX_API int mdbx_env_chk(MDBX_env *env, const MDBX_chk_callbacks_t *cb, MDBX
 * \returns Нулевое значение в случае успеха, иначе код ошибки. */
 LIBMDBX_API int mdbx_env_chk_encount_problem(MDBX_chk_context_t *ctx);

+LIBMDBX_API const char *mdbx_ratio2digits(uint64_t numerator, uint64_t denominator, int precision, char *buffer,
+                                          size_t buffer_size);
+
+LIBMDBX_API const char *mdbx_ratio2percents(uint64_t value, uint64_t whole, char *buffer, size_t buffer_size);
+
 /** end of chk @} */

 /** end of c_api @} */
--- a/mdbx.h++
+++ b/mdbx.h++
@@ -6415,6 +6415,12 @@ template <> struct hash<::mdbx::slice> {
  MDBX_CXX14_CONSTEXPR size_t operator()(::mdbx::slice const &slice) const noexcept { return slice.hash_value(); }
 };

+template <class ALLOCATOR, typename CAPACITY_POLICY> struct hash<::mdbx::buffer<ALLOCATOR, CAPACITY_POLICY>> {
+  MDBX_CXX14_CONSTEXPR size_t operator()(::mdbx::buffer<ALLOCATOR, CAPACITY_POLICY> const &buffer) const noexcept {
+    return buffer.hash_value();
+  }
+};
+
 /// end cxx_api @}
 } // namespace std

--- a/packages/buildroot/0001-package-libmdbx-new-package-library-database.patch
+++ b/packages/buildroot/0001-package-libmdbx-new-package-library-database.patch
@@ -1,13 +1,13 @@
-From f2f1f6e76c1538d044b552d9e7ecedc3433e6cd9 Mon Sep 17 00:00:00 2001
+From b2f1297dd2cd42cc0e04f1900fbf6da6c2694b7b Mon Sep 17 00:00:00 2001
 From: =?UTF-8?q?=D0=9B=D0=B5=D0=BE=D0=BD=D0=B8=D0=B4=20=D0=AE=D1=80=D1=8C?=
 =?UTF-8?q?=D0=B5=D0=B2=20=28Leonid=20Yuriev=29?= <leo@yuriev.ru>
-Date: Sun, 3 Aug 2025 23:59:11 +0300
+Date: Fri, 31 Oct 2025 16:58:31 +0300
 Subject: [PATCH] package/libmdbx: new package (library/database).
 MIME-Version: 1.0
 Content-Type: text/plain; charset=UTF-8
 Content-Transfer-Encoding: 8bit

-This patch adds libmdbx:
+This patch adds libmdbx 0.13.9:
 - libmdbx is one of the fastest compact embeddable key-value ACID database.
 - libmdbx has a specific set of properties and capabilities,
   focused on creating unique lightweight solutions.
@@ -15,158 +15,55 @@ This patch adds libmdbx:
   in terms of reliability, features and performance.
 - more information at https://libmdbx.dqdkfa.ru

-The 0.13.7 "Дружба" (Friendship) is stable release of _libmdbx_ branch with new superior features.
-
-The complete ChangeLog: https://gitflic.ru/project/erthink/libmdbx/blob?file=ChangeLog.md
+The 0.13.9 "ИС-2" (IS-2) is bugfix release of the stable branch.
+For more information please see [ChangeLog](https://github.com/erthink/libmdbx/blob/stable/ChangeLog.md).

 Signed-off-by: Леонид Юрьев (Leonid Yuriev) <leo@yuriev.ru>
 ---
- DEVELOPERS                   |  3 +++
- package/Config.in            |  1 +
- package/libmdbx/Config.in    | 45 ++++++++++++++++++++++++++++++++++++
- package/libmdbx/libmdbx.hash |  6 +++++
- package/libmdbx/libmdbx.mk   | 41 ++++++++++++++++++++++++++++++++
- 5 files changed, 96 insertions(+)
- create mode 100644 package/libmdbx/Config.in
- create mode 100644 package/libmdbx/libmdbx.hash
- create mode 100644 package/libmdbx/libmdbx.mk
+ package/libmdbx/Config.in    | 4 +++-
+ package/libmdbx/libmdbx.hash | 2 +-
+ package/libmdbx/libmdbx.mk   | 2 +-
+ 3 files changed, 5 insertions(+), 3 deletions(-)

-diff --git a/DEVELOPERS b/DEVELOPERS
-index 9ab1e125f4..758ff6a2d5 100644
--- a/DEVELOPERS
-+++ b/DEVELOPERS
-@@ -1482,6 +1482,9 @@ N:	Leon Anavi <leon.anavi@konsulko.com>
- F:	board/olimex/a10_olinuxino
- F:	configs/olimex_a10_olinuxino_lime_defconfig
- 
-+N:	Leonid Yuriev <leo@yuriev.ru>
-+F:	package/libmdbx/
-+
- N:	Lionel Flandrin <lionel@svkt.org>
- F:	package/python-babel/
- F:	package/python-daemonize/
-diff --git a/package/Config.in b/package/Config.in
-index 016a99ed1a..a6f95bfaa9 100644
--- a/package/Config.in
-+++ b/package/Config.in
-@@ -1372,6 +1372,7 @@ menu "Database"
- 	source "package/kompexsqlite/Config.in"
- 	source "package/leveldb/Config.in"
- 	source "package/libgit2/Config.in"
-+	source "package/libmdbx/Config.in"
- 	source "package/libodb/Config.in"
- 	source "package/libodb-boost/Config.in"
- 	source "package/libodb-mysql/Config.in"
 diff --git a/package/libmdbx/Config.in b/package/libmdbx/Config.in
-new file mode 100644
-index 0000000000..a9a4ac45c5
--- /dev/null
+index a9a4ac45c5..1640dbd9de 100644
+--- a/package/libmdbx/Config.in
 +++ b/package/libmdbx/Config.in
-@@ -0,0 +1,45 @@
-+config BR2_PACKAGE_LIBMDBX
-+	bool "libmdbx"
-+	depends on BR2_USE_MMU
-+	depends on BR2_TOOLCHAIN_HAS_SYNC_4
-+	depends on BR2_TOOLCHAIN_HAS_THREADS
-+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
-+	help
-+	  One of the fastest compact key-value ACID database
-+	  without WAL. libmdbx has a specific set of properties
-+	  and capabilities, focused on creating unique lightweight
-+	  solutions.
-+
-+	  libmdbx surpasses the legendary LMDB in terms of
-+	  reliability, features and performance.
-+
-+	  https://libmdbx.dqdkfa.ru
-+
-+if BR2_PACKAGE_LIBMDBX
-+
-+config BR2_PACKAGE_LIBMDBX_TOOLS
-+	bool "install tools"
-+	help
-+	  Install libmdbx tools for checking, dump, restore
-+	  and show statistics of databases.
-+
-+config BR2_PACKAGE_LIBMDBX_CXX
-+	bool "C++ API"
-+	depends on BR2_INSTALL_LIBSTDCPP
-+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_8
-+	depends on !BR2_TOOLCHAIN_HAS_GCC_BUG_64735
-+	help
-+	  Enable modern C++11/14/17/20 API for libmdbx.
-+
-+comment "libmdbx C++ support needs a toolchain w/ C++11, gcc >= 4.8 w/o bug#64735"
-+	depends on !BR2_INSTALL_LIBSTDCPP || \
-+		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_8 || \
-+		BR2_TOOLCHAIN_HAS_GCC_BUG_64735
-+
-+endif
-+
-+comment "libmdbx needs MMU, a toolchain w/ threads, gcc >= 4.4 w/ 4-byte atomics"
-+	depends on BR2_USE_MMU
-+	depends on !BR2_TOOLCHAIN_HAS_THREADS || \
-+		!BR2_TOOLCHAIN_HAS_SYNC_4 || \
-+		!BR2_TOOLCHAIN_GCC_AT_LEAST_4_4
+@@ -11,7 +11,9 @@ config BR2_PACKAGE_LIBMDBX
+ 	  solutions.
+ 
+ 	  libmdbx surpasses the legendary LMDB in terms of
+-	  reliability, features and performance.
+	  reliability, features and performance. At the end of 2024
+	  libmdbx was chosen by all modern Ethereum frontiers/nodes
+	  as a storage engine.
+ 
+ 	  https://libmdbx.dqdkfa.ru
+ 
 diff --git a/package/libmdbx/libmdbx.hash b/package/libmdbx/libmdbx.hash
-new file mode 100644
-index 0000000000..8c7efb184b
--- /dev/null
+index ae5266716b..4a4f302015 100644
+--- a/package/libmdbx/libmdbx.hash
 +++ b/package/libmdbx/libmdbx.hash
-@@ -0,0 +1,6 @@
-+# Hashes from: https://libmdbx.dqdkfa.ru/release/SHA256SUMS
-+sha256  d00c1287ec6bbc366363ccdd3eea97bd470ccb5cc102d56b341f84a9fba7e8e9  libmdbx-amalgamated-0.13.7.tar.xz
-+
-+# Locally calculated
-+sha256  0d542e0c8804e39aa7f37eb00da5a762149dc682d7829451287e11b938e94594  LICENSE
-+sha256  651f71b46c6bb0046d2122df7f9def9cb24f4dc28c5b11cef059f66565cda30f  NOTICE
+@@ -1,5 +1,5 @@
+ # Hashes from: https://libmdbx.dqdkfa.ru/release/SHA256SUMS
+-sha256  57db987de6f7ccc66a66ae28a7bda9f9fbb48ac5fb9279bcca92fd5de13075d1  libmdbx-amalgamated-0.13.6.tar.xz
+sha256  63d2608c8f7c23185c0d27d817d42dd720e84973224ffc584c7f7b522f5f06fe  libmdbx-amalgamated-0.13.9.tar.xz
+ 
+ # Locally calculated
+ sha256  0d542e0c8804e39aa7f37eb00da5a762149dc682d7829451287e11b938e94594  LICENSE
 diff --git a/package/libmdbx/libmdbx.mk b/package/libmdbx/libmdbx.mk
-new file mode 100644
-index 0000000000..bbb37f21a6
--- /dev/null
+index f461d98397..62817a98f8 100644
+--- a/package/libmdbx/libmdbx.mk
 +++ b/package/libmdbx/libmdbx.mk
-@@ -0,0 +1,41 @@
-+################################################################################
-+#
-+# libmdbx
-+#
-+################################################################################
-+
-+LIBMDBX_VERSION = 0.13.7
-+LIBMDBX_SOURCE = libmdbx-amalgamated-$(LIBMDBX_VERSION).tar.xz
-+LIBMDBX_SITE = https://libmdbx.dqdkfa.ru/release
-+LIBMDBX_SUPPORTS_IN_SOURCE_BUILD = NO
-+LIBMDBX_LICENSE = Apache-2.0
-+LIBMDBX_LICENSE_FILES = LICENSE NOTICE
-+LIBMDBX_STRIP_COMPONENTS = 0
-+LIBMDBX_INSTALL_STAGING = YES
-+
-+# Set CMAKE_BUILD_TYPE to Release to remove -Werror and avoid a build failure
-+# with glibc < 2.12
-+LIBMDBX_CONF_OPTS = \
-+	-DCMAKE_BUILD_TYPE=Release \
-+	-DMDBX_INSTALL_MANPAGES=OFF \
-+	-DBUILD_FOR_NATIVE_CPU=OFF \
-+	-DMDBX_BUILD_CXX=$(if $(BR2_PACKAGE_LIBMDBX_CXX),ON,OFF) \
-+	-DMDBX_BUILD_TOOLS=$(if $(BR2_PACKAGE_LIBMDBX_TOOLS),ON,OFF)
-+
-+ifeq ($(BR2_STATIC_LIBS)$(BR2_SHARED_STATIC_LIBS),y)
-+LIBMDBX_CONF_OPTS += -DMDBX_INSTALL_STATIC=ON
-+else
-+LIBMDBX_CONF_OPTS += -DMDBX_INSTALL_STATIC=OFF
-+endif
-+
-+ifeq ($(BR2_SHARED_LIBS)$(BR2_SHARED_STATIC_LIBS),y)
-+LIBMDBX_CONF_OPTS += \
-+	-DMDBX_BUILD_SHARED_LIBRARY=ON \
-+	-DMDBX_LINK_TOOLS_NONSTATIC=ON
-+else
-+LIBMDBX_CONF_OPTS += \
-+	-DMDBX_BUILD_SHARED_LIBRARY=OFF \
-+	-DMDBX_LINK_TOOLS_NONSTATIC=OFF
-+endif
-+
-+$(eval $(cmake-package))
+@@ -4,7 +4,7 @@
+ #
+ ################################################################################
+ 
+-LIBMDBX_VERSION = 0.13.6
+LIBMDBX_VERSION = 0.13.9
+ LIBMDBX_SOURCE = libmdbx-amalgamated-$(LIBMDBX_VERSION).tar.xz
+ LIBMDBX_SITE = https://libmdbx.dqdkfa.ru/release
+ LIBMDBX_SUPPORTS_IN_SOURCE_BUILD = NO
 -- 
-2.50.1
+2.51.2

--- a/src/api-copy.c
+++ b/src/api-copy.c
@@ -479,7 +479,7 @@ __cold static int copy_with_compacting(MDBX_env *env, MDBX_txn *txn, mdbx_fileha
  if (meta->geometry.now != meta->geometry.first_unallocated) {
    const size_t whole_size = pgno2bytes(env, meta->geometry.now);
    if (!dest_is_pipe)
-      return osal_fallocate(fd, whole_size);
+      return osal_fsetsize(fd, whole_size);

    const size_t used_size = pgno2bytes(env, meta->geometry.first_unallocated);
    memset(data_buffer, 0, (size_t)MDBX_ENVCOPY_WRITEBUF);
@@ -648,7 +648,7 @@ retry_snap_meta:
  /* Extend file if required */
  if (likely(rc == MDBX_SUCCESS) && whole_size != used_size) {
    if (!dest_is_pipe)
-      rc = osal_fallocate(fd, whole_size);
+      rc = osal_fsetsize(fd, whole_size);
    else {
      memset(data_buffer, 0, (size_t)MDBX_ENVCOPY_WRITEBUF);
      for (size_t offset = used_size; rc == MDBX_SUCCESS && offset < whole_size;) {
--- a/src/api-dbi.c
+++ b/src/api-dbi.c
@@ -241,7 +241,7 @@ __cold int mdbx_dbi_stat(const MDBX_txn *txn, MDBX_dbi dbi, MDBX_stat *dest, siz
    return LOG_IFERR(MDBX_BAD_TXN);

  if (unlikely(txn->dbi_state[dbi] & DBI_STALE)) {
-    rc = tbl_fetch((MDBX_txn *)txn, dbi);
+    rc = tbl_refresh((MDBX_txn *)txn, dbi);
    if (unlikely(rc != MDBX_SUCCESS))
      return LOG_IFERR(rc);
  }
--- a/src/api-env.c
+++ b/src/api-env.c
@@ -245,7 +245,8 @@ __cold int mdbx_env_create(MDBX_env **penv) {

 #if defined(_WIN32) || defined(_WIN64)
  imports.srwl_Init(&env->remap_guard);
-  InitializeCriticalSection(&env->windowsbug_lock);
+  InitializeCriticalSection(&env->lck_event_cs);
+  InitializeCriticalSection(&env->dxb_event_cs);
 #else
  rc = osal_fastmutex_init(&env->remap_guard);
  if (unlikely(rc != MDBX_SUCCESS)) {
@@ -638,7 +639,8 @@ __cold int mdbx_env_close_ex(MDBX_env *env, bool dont_sync) {
  ENSURE(env, osal_fastmutex_destroy(&env->dbi_lock) == MDBX_SUCCESS);
 #if defined(_WIN32) || defined(_WIN64)
  /* remap_guard don't have destructor (Slim Reader/Writer Lock) */
-  DeleteCriticalSection(&env->windowsbug_lock);
+  DeleteCriticalSection(&env->lck_event_cs);
+  DeleteCriticalSection(&env->dxb_event_cs);
 #else
  ENSURE(env, osal_fastmutex_destroy(&env->remap_guard) == MDBX_SUCCESS);
 #endif /* Windows */
@@ -664,11 +666,68 @@ __cold int mdbx_env_close_ex(MDBX_env *env, bool dont_sync) {

 /*----------------------------------------------------------------------------*/

-static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo *out, const size_t bytes,
-                         troika_t *const troika) {
-  const size_t size_before_bootid = offsetof(MDBX_envinfo, mi_bootid);
-  const size_t size_before_pgop_stat = offsetof(MDBX_envinfo, mi_pgop_stat);
-  const size_t size_before_dxbid = offsetof(MDBX_envinfo, mi_dxbid);
+__must_check_result static int env_info_sys(const MDBX_env *env, MDBX_envinfo *out) {
+  out->mi_bootid.current.x = globals.bootid.x;
+  out->mi_bootid.current.y = globals.bootid.y;
+  out->mi_sys_pagesize = globals.sys_pagesize;
+#ifdef __OpenBSD__
+  out->mi_sys_upcblk = 0;
+#elif defined(_WIN32) || defined(_WIN64)
+  out->mi_sys_upcblk = globals.sys_allocation_granularity;
+#elif defined(AT_UCACHEBSIZE)
+  out->mi_sys_upcblk = globals.sys_unified_cache_block;
+#else
+  out->mi_sys_upcblk = globals.sys_pagesize;
+#endif /* AT_UCACHEBSIZE */
+
+  out->mi_dxb_fsize = 0;
+  out->mi_dxb_fallocated = 0;
+  out->mi_sys_ioblk = 0;
+  if (env->dxb_mmap.fd != INVALID_HANDLE_VALUE) {
+#if defined(_WIN32) || defined(_WIN64)
+    union {
+      BY_HANDLE_FILE_INFORMATION bh;
+      FILE_STANDARD_INFO std;
+#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
+      FILE_STORAGE_INFO storage;
+#endif
+    } sys_finfo;
+    if (imports.GetFileInformationByHandleEx &&
+        imports.GetFileInformationByHandleEx(env->dxb_mmap.fd, FileStandardInfo, &sys_finfo.std,
+                                             sizeof(sys_finfo.std))) {
+      out->mi_dxb_fsize = sys_finfo.std.EndOfFile.QuadPart;
+      out->mi_dxb_fallocated = sys_finfo.std.AllocationSize.QuadPart;
+#if _WIN32_WINNT >= _WIN32_WINNT_WIN8
+      if (imports.GetFileInformationByHandleEx(env->dxb_mmap.fd, FileStorageInfo, &sys_finfo.storage,
+                                               sizeof(sys_finfo.storage))) {
+        out->mi_sys_ioblk = (sys_finfo.storage.FileSystemEffectivePhysicalBytesPerSectorForAtomicity >
+                             sys_finfo.storage.LogicalBytesPerSector)
+                                ? sys_finfo.storage.FileSystemEffectivePhysicalBytesPerSectorForAtomicity
+                                : sys_finfo.storage.LogicalBytesPerSector;
+      }
+#endif
+    } else if (GetFileInformationByHandle(env->dxb_mmap.fd, &sys_finfo.bh)) {
+      out->mi_dxb_fsize = sys_finfo.bh.nFileSizeLow | (uint64_t)sys_finfo.bh.nFileSizeHigh << 32;
+    } else
+      return GetLastError();
+#else
+    struct stat sys_fstat;
+    if (fstat(env->dxb_mmap.fd, &sys_fstat))
+      return errno;
+    out->mi_dxb_fsize = sys_fstat.st_size;
+    out->mi_dxb_fallocated = UINT64_C(512) * sys_fstat.st_blocks;
+    out->mi_sys_ioblk = sys_fstat.st_blksize;
+#endif /* !Windows */
+  }
+  return MDBX_SUCCESS;
+}
+
+__must_check_result static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo *out,
+                                             troika_t *const troika) {
+  int err = env_info_sys(env, out);
+  if (unlikely(err != MDBX_SUCCESS))
+    return err;
+
  if (unlikely(env->flags & ENV_FATAL_ERROR))
    return MDBX_PANIC;

@@ -678,7 +737,6 @@ static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo
    /* environment not yet opened */
 #if 1
    /* default behavior: returns the available info but zeroed the rest */
-    memset(out, 0, bytes);
    out->mi_geo.lower = env->geo_in_bytes.lower;
    out->mi_geo.upper = env->geo_in_bytes.upper;
    out->mi_geo.shrink = env->geo_in_bytes.shrink;
@@ -686,11 +744,6 @@ static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo
    out->mi_geo.current = env->geo_in_bytes.now;
    out->mi_maxreaders = env->max_readers;
    out->mi_dxb_pagesize = env->ps;
-    out->mi_sys_pagesize = globals.sys_pagesize;
-    if (likely(bytes > size_before_bootid)) {
-      out->mi_bootid.current.x = globals.bootid.x;
-      out->mi_bootid.current.y = globals.bootid.y;
-    }
    return MDBX_SUCCESS;
 #else
    /* some users may prefer this behavior: return appropriate error */
@@ -710,13 +763,10 @@ static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo
  out->mi_meta_sign[1] = unaligned_peek_u64(4, meta1->sign);
  out->mi_meta_txnid[2] = troika->txnid[2];
  out->mi_meta_sign[2] = unaligned_peek_u64(4, meta2->sign);
-  if (likely(bytes > size_before_bootid)) {
-    memcpy(&out->mi_bootid.meta[0], &meta0->bootid, 16);
-    memcpy(&out->mi_bootid.meta[1], &meta1->bootid, 16);
-    memcpy(&out->mi_bootid.meta[2], &meta2->bootid, 16);
-    if (likely(bytes > size_before_dxbid))
-      memcpy(&out->mi_dxbid, &meta0->dxbid, 16);
-  }
+  memcpy(&out->mi_bootid.meta[0], &meta0->bootid, 16);
+  memcpy(&out->mi_bootid.meta[1], &meta1->bootid, 16);
+  memcpy(&out->mi_bootid.meta[2], &meta2->bootid, 16);
+  memcpy(&out->mi_dxbid, &meta0->dxbid, 16);

  const volatile meta_t *txn_meta = head.ptr_v;
  out->mi_last_pgno = txn_meta->geometry.first_unallocated - 1;
@@ -740,44 +790,38 @@ static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo
  out->mi_maxreaders = env->max_readers;
  out->mi_numreaders = env->lck_mmap.lck ? atomic_load32(&lck->rdt_length, mo_Relaxed) : INT32_MAX;
  out->mi_dxb_pagesize = env->ps;
-  out->mi_sys_pagesize = globals.sys_pagesize;

-  if (likely(bytes > size_before_bootid)) {
-    const uint64_t unsynced_pages =
-        atomic_load64(&lck->unsynced_pages, mo_Relaxed) +
-        ((uint32_t)out->mi_recent_txnid != atomic_load32(&lck->meta_sync_txnid, mo_Relaxed));
-    out->mi_unsync_volume = pgno2bytes(env, (size_t)unsynced_pages);
-    const uint64_t monotime_now = osal_monotime();
-    uint64_t ts = atomic_load64(&lck->eoos_timestamp, mo_Relaxed);
-    out->mi_since_sync_seconds16dot16 = ts ? osal_monotime_to_16dot16_noUnderflow(monotime_now - ts) : 0;
-    ts = atomic_load64(&lck->readers_check_timestamp, mo_Relaxed);
-    out->mi_since_reader_check_seconds16dot16 = ts ? osal_monotime_to_16dot16_noUnderflow(monotime_now - ts) : 0;
-    out->mi_autosync_threshold = pgno2bytes(env, atomic_load32(&lck->autosync_threshold, mo_Relaxed));
-    out->mi_autosync_period_seconds16dot16 =
-        osal_monotime_to_16dot16_noUnderflow(atomic_load64(&lck->autosync_period, mo_Relaxed));
-    out->mi_bootid.current.x = globals.bootid.x;
-    out->mi_bootid.current.y = globals.bootid.y;
-    out->mi_mode = env->lck_mmap.lck ? lck->envmode.weak : env->flags;
-  }
+  const uint64_t unsynced_pages = atomic_load64(&lck->unsynced_pages, mo_Relaxed) +
+                                  ((uint32_t)out->mi_recent_txnid != atomic_load32(&lck->meta_sync_txnid, mo_Relaxed));
+  out->mi_unsync_volume = pgno2bytes(env, (size_t)unsynced_pages);
+  const uint64_t monotime_now = osal_monotime();
+  uint64_t ts = atomic_load64(&lck->eoos_timestamp, mo_Relaxed);
+  out->mi_since_sync_seconds16dot16 = ts ? osal_monotime_to_16dot16_noUnderflow(monotime_now - ts) : 0;
+  ts = atomic_load64(&lck->readers_check_timestamp, mo_Relaxed);
+  out->mi_since_reader_check_seconds16dot16 = ts ? osal_monotime_to_16dot16_noUnderflow(monotime_now - ts) : 0;
+  out->mi_autosync_threshold = pgno2bytes(env, atomic_load32(&lck->autosync_threshold, mo_Relaxed));
+  out->mi_autosync_period_seconds16dot16 =
+      osal_monotime_to_16dot16_noUnderflow(atomic_load64(&lck->autosync_period, mo_Relaxed));
+  out->mi_bootid.current.x = globals.bootid.x;
+  out->mi_bootid.current.y = globals.bootid.y;
+  out->mi_mode = env->lck_mmap.lck ? lck->envmode.weak : env->flags;

-  if (likely(bytes > size_before_pgop_stat)) {
 #if MDBX_ENABLE_PGOP_STAT
-    out->mi_pgop_stat.newly = atomic_load64(&lck->pgops.newly, mo_Relaxed);
-    out->mi_pgop_stat.cow = atomic_load64(&lck->pgops.cow, mo_Relaxed);
-    out->mi_pgop_stat.clone = atomic_load64(&lck->pgops.clone, mo_Relaxed);
-    out->mi_pgop_stat.split = atomic_load64(&lck->pgops.split, mo_Relaxed);
-    out->mi_pgop_stat.merge = atomic_load64(&lck->pgops.merge, mo_Relaxed);
-    out->mi_pgop_stat.spill = atomic_load64(&lck->pgops.spill, mo_Relaxed);
-    out->mi_pgop_stat.unspill = atomic_load64(&lck->pgops.unspill, mo_Relaxed);
-    out->mi_pgop_stat.wops = atomic_load64(&lck->pgops.wops, mo_Relaxed);
-    out->mi_pgop_stat.prefault = atomic_load64(&lck->pgops.prefault, mo_Relaxed);
-    out->mi_pgop_stat.mincore = atomic_load64(&lck->pgops.mincore, mo_Relaxed);
-    out->mi_pgop_stat.msync = atomic_load64(&lck->pgops.msync, mo_Relaxed);
-    out->mi_pgop_stat.fsync = atomic_load64(&lck->pgops.fsync, mo_Relaxed);
+  out->mi_pgop_stat.newly = atomic_load64(&lck->pgops.newly, mo_Relaxed);
+  out->mi_pgop_stat.cow = atomic_load64(&lck->pgops.cow, mo_Relaxed);
+  out->mi_pgop_stat.clone = atomic_load64(&lck->pgops.clone, mo_Relaxed);
+  out->mi_pgop_stat.split = atomic_load64(&lck->pgops.split, mo_Relaxed);
+  out->mi_pgop_stat.merge = atomic_load64(&lck->pgops.merge, mo_Relaxed);
+  out->mi_pgop_stat.spill = atomic_load64(&lck->pgops.spill, mo_Relaxed);
+  out->mi_pgop_stat.unspill = atomic_load64(&lck->pgops.unspill, mo_Relaxed);
+  out->mi_pgop_stat.wops = atomic_load64(&lck->pgops.wops, mo_Relaxed);
+  out->mi_pgop_stat.prefault = atomic_load64(&lck->pgops.prefault, mo_Relaxed);
+  out->mi_pgop_stat.mincore = atomic_load64(&lck->pgops.mincore, mo_Relaxed);
+  out->mi_pgop_stat.msync = atomic_load64(&lck->pgops.msync, mo_Relaxed);
+  out->mi_pgop_stat.fsync = atomic_load64(&lck->pgops.fsync, mo_Relaxed);
 #else
-    memset(&out->mi_pgop_stat, 0, sizeof(out->mi_pgop_stat));
+  memset(&out->mi_pgop_stat, 0, sizeof(out->mi_pgop_stat));
 #endif /* MDBX_ENABLE_PGOP_STAT*/
-  }

  txnid_t overall_latter_reader_txnid = out->mi_recent_txnid;
  txnid_t self_latter_reader_txnid = overall_latter_reader_txnid;
@@ -800,22 +844,21 @@ static int env_info_snap(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo
  return MDBX_SUCCESS;
 }

-__cold int env_info(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo *out, size_t bytes, troika_t *troika) {
+__cold int env_info(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo *out, troika_t *troika) {
  MDBX_envinfo snap;
-  int rc = env_info_snap(env, txn, &snap, sizeof(snap), troika);
+  int rc = env_info_snap(env, txn, &snap, troika);
  if (unlikely(rc != MDBX_SUCCESS))
    return rc;

-  eASSERT(env, sizeof(snap) >= bytes);
  while (1) {
-    rc = env_info_snap(env, txn, out, bytes, troika);
+    rc = env_info_snap(env, txn, out, troika);
    if (unlikely(rc != MDBX_SUCCESS))
      return rc;
    snap.mi_since_sync_seconds16dot16 = out->mi_since_sync_seconds16dot16;
    snap.mi_since_reader_check_seconds16dot16 = out->mi_since_reader_check_seconds16dot16;
-    if (likely(memcmp(&snap, out, bytes) == 0))
+    if (likely(memcmp(&snap, out, sizeof(MDBX_envinfo)) == 0))
      return MDBX_SUCCESS;
-    memcpy(&snap, out, bytes);
+    memcpy(&snap, out, sizeof(MDBX_envinfo));
  }
 }

@@ -823,11 +866,7 @@ __cold int mdbx_env_info_ex(const MDBX_env *env, const MDBX_txn *txn, MDBX_envin
  if (unlikely((env == nullptr && txn == nullptr) || arg == nullptr))
    return LOG_IFERR(MDBX_EINVAL);

-  const size_t size_before_bootid = offsetof(MDBX_envinfo, mi_bootid);
-  const size_t size_before_pgop_stat = offsetof(MDBX_envinfo, mi_pgop_stat);
-  const size_t size_before_dxbid = offsetof(MDBX_envinfo, mi_dxbid);
-  if (unlikely(bytes != sizeof(MDBX_envinfo)) && bytes != size_before_bootid && bytes != size_before_pgop_stat &&
-      bytes != size_before_dxbid)
+  if (unlikely(bytes != sizeof(MDBX_envinfo)))
    return LOG_IFERR(MDBX_EINVAL);

  if (txn) {
@@ -846,7 +885,7 @@ __cold int mdbx_env_info_ex(const MDBX_env *env, const MDBX_txn *txn, MDBX_envin
  }

  troika_t troika;
-  return LOG_IFERR(env_info(env, txn, arg, bytes, &troika));
+  return LOG_IFERR(env_info(env, txn, arg, &troika));
 }

 __cold int mdbx_preopen_snapinfo(const char *pathname, MDBX_envinfo *out, size_t bytes) {
@@ -865,27 +904,18 @@ __cold int mdbx_preopen_snapinfoW(const wchar_t *pathname, MDBX_envinfo *out, si
  if (unlikely(!out))
    return LOG_IFERR(MDBX_EINVAL);

-  const size_t size_before_bootid = offsetof(MDBX_envinfo, mi_bootid);
-  const size_t size_before_pgop_stat = offsetof(MDBX_envinfo, mi_pgop_stat);
-  const size_t size_before_dxbid = offsetof(MDBX_envinfo, mi_dxbid);
-  if (unlikely(bytes != sizeof(MDBX_envinfo)) && bytes != size_before_bootid && bytes != size_before_pgop_stat &&
-      bytes != size_before_dxbid)
+  if (unlikely(bytes != sizeof(MDBX_envinfo)))
    return LOG_IFERR(MDBX_EINVAL);

-  memset(out, 0, bytes);
-  if (likely(bytes > size_before_bootid)) {
-    out->mi_bootid.current.x = globals.bootid.x;
-    out->mi_bootid.current.y = globals.bootid.y;
-  }
-
-  MDBX_env env;
-  memset(&env, 0, sizeof(env));
-  env.pid = osal_getpid();
  if (unlikely(!is_powerof2(globals.sys_pagesize) || globals.sys_pagesize < MDBX_MIN_PAGESIZE)) {
    ERROR("unsuitable system pagesize %u", globals.sys_pagesize);
    return LOG_IFERR(MDBX_INCOMPATIBLE);
  }
-  out->mi_sys_pagesize = globals.sys_pagesize;
+
+  memset(out, 0, bytes);
+  MDBX_env env;
+  memset(&env, 0, sizeof(env));
+  env.pid = osal_getpid();
  env.flags = MDBX_RDONLY | MDBX_NORDAHEAD | MDBX_ACCEDE | MDBX_VALIDATION;
  env.stuck_meta = -1;
  env.lck_mmap.fd = INVALID_HANDLE_VALUE;
@@ -894,11 +924,12 @@ __cold int mdbx_preopen_snapinfoW(const wchar_t *pathname, MDBX_envinfo *out, si
  env.fd4meta = INVALID_HANDLE_VALUE;
 #if defined(_WIN32) || defined(_WIN64)
  env.dxb_lock_event = INVALID_HANDLE_VALUE;
+  env.lck_lock_event = INVALID_HANDLE_VALUE;
  env.ioring.overlapped_fd = INVALID_HANDLE_VALUE;
 #endif /* Windows */
  env_options_init(&env);

-  int rc = env_handle_pathname(&env, pathname, 0);
+  int err, rc = env_handle_pathname(&env, pathname, 0);
  if (unlikely(rc != MDBX_SUCCESS))
    goto bailout;
  rc = osal_openfile(MDBX_OPEN_DXB_READ, &env, env.pathname.dxb, &env.lazy_fd, 0);
@@ -918,17 +949,17 @@ __cold int mdbx_preopen_snapinfoW(const wchar_t *pathname, MDBX_envinfo *out, si
  out->mi_geo.current = pgno2bytes(&env, header.geometry.now);
  out->mi_last_pgno = header.geometry.first_unallocated - 1;

-  const unsigned n = 0;
  out->mi_recent_txnid = constmeta_txnid(&header);
+  const unsigned n = 0;
  out->mi_meta_sign[n] = unaligned_peek_u64(4, &header.sign);
-  if (likely(bytes > size_before_bootid)) {
-    memcpy(&out->mi_bootid.meta[n], &header.bootid, 16);
-    if (likely(bytes > size_before_dxbid))
-      memcpy(&out->mi_dxbid, &header.dxbid, 16);
-  }
+  memcpy(&out->mi_bootid.meta[n], &header.bootid, 16);
+  memcpy(&out->mi_dxbid, &header.dxbid, 16);

 bailout:
-  env_close(&env, false);
+  err = env_info_sys(&env, out);
+  rc = rc ? rc : err;
+  err = env_close(&env, false);
+  rc = rc ? rc : err;
  return LOG_IFERR(rc);
 }

@@ -1100,13 +1131,16 @@ __cold int mdbx_env_set_geometry(MDBX_env *env, intptr_t size_lower, intptr_t si
  }

  const size_t unit_ps = (globals.sys_pagesize > (size_t)pagesize) ? globals.sys_pagesize : (size_t)pagesize;
-  const size_t unit_ag = (globals.sys_allocation_granularity > unit_ps) ? globals.sys_allocation_granularity : unit_ps;
+  const size_t unit_ag = (globals.sys_allocation_granularity > unit_ps &&
+                          (growth_step < 0 || (size_t)growth_step >= globals.sys_allocation_granularity))
+                             ? globals.sys_allocation_granularity
+                             : unit_ps;
  size_lower = ceil_powerof2(size_lower, unit_ps);
  size_upper = ceil_powerof2(size_upper, unit_ag);
  size_now = ceil_powerof2(size_now, unit_ag);

  /* LY: подбираем значение size_upper:
-   *  - кратное размеру страницы
+   *  - кратное размеру unit_ag (размеру страницы БД и системному размеру выделения)
   *  - без нарушения MAX_MAPSIZE и MAX_PAGENO */
  while (unlikely((size_t)size_upper > MAX_MAPSIZE || (uint64_t)size_upper / pagesize > MAX_PAGENO + 1)) {
    if ((size_t)size_upper < unit_ag + MIN_MAPSIZE || (size_t)size_upper < (size_t)pagesize * (MIN_PAGENO + 1)) {
--- a/src/api-extra.c
+++ b/src/api-extra.c
@@ -163,3 +163,29 @@ int mdbx_txn_unlock(MDBX_env *env) {
  lck_txn_unlock(env);
  return MDBX_SUCCESS;
 }
+
+/*------------------------------------------------------------------------------
+ * Auxiliary */
+
+__cold const char *mdbx_ratio2digits(uint64_t numerator, uint64_t denominator, int precision, char *buffer,
+                                     size_t buffer_size) {
+  if (!buffer)
+    return "nullptr";
+  else if (buffer_size < sizeof(ratio2digits_buffer_t))
+    return "buffer-to-small";
+  else if (!denominator)
+    return numerator ? "infinity" : "undefined";
+  else
+    return ratio2digits(numerator, denominator, (ratio2digits_buffer_t *)buffer, precision);
+}
+
+__cold const char *mdbx_ratio2percents(uint64_t value, uint64_t whole, char *buffer, size_t buffer_size) {
+  if (!buffer)
+    return "nullptr";
+  else if (buffer_size < sizeof(ratio2digits_buffer_t))
+    return "buffer-to-small";
+  else if (!whole)
+    return value ? "infinity" : "undefined";
+  else
+    return ratio2percent(value, whole, (ratio2digits_buffer_t *)buffer);
+}
--- a/src/api-key-transform.c
+++ b/src/api-key-transform.c
@@ -124,7 +124,7 @@ uint64_t mdbx_key_from_jsonInteger(const int64_t json_integer) {
    const uint64_t exponent = (uint64_t)IEEE754_DOUBLE_EXPONENTA_BIAS + IEEE754_DOUBLE_MANTISSA_SIZE - shift;
    assert(exponent > 0 && exponent <= IEEE754_DOUBLE_EXPONENTA_MAX);
    const uint64_t key = bias + (exponent << IEEE754_DOUBLE_MANTISSA_SIZE) + (mantissa - IEEE754_DOUBLE_IMPLICIT_LEAD);
-#if !defined(_MSC_VER) || defined(_DEBUG) /* Workaround for MSVC error LNK2019: unresolved external                    \
+#if !defined(_MSC_VER) || !MDBX_WITHOUT_MSVC_CRT /* Workaround for MSVC error LNK2019: unresolved external             \
                                             symbol __except1 referenced in function __ftol3_except */
    assert(key == mdbx_key_from_double((double)json_integer));
 #endif /* Workaround for MSVC */
@@ -146,7 +146,7 @@ uint64_t mdbx_key_from_jsonInteger(const int64_t json_integer) {
    assert(exponent > 0 && exponent <= IEEE754_DOUBLE_EXPONENTA_MAX);
    const uint64_t key =
        bias - 1 - (exponent << IEEE754_DOUBLE_MANTISSA_SIZE) - (mantissa - IEEE754_DOUBLE_IMPLICIT_LEAD);
-#if !defined(_MSC_VER) || defined(_DEBUG) /* Workaround for MSVC error LNK2019: unresolved external                    \
+#if !defined(_MSC_VER) || !MDBX_WITHOUT_MSVC_CRT /* Workaround for MSVC error LNK2019: unresolved external             \
                                             symbol __except1 referenced in function __ftol3_except */
    assert(key == mdbx_key_from_double((double)json_integer));
 #endif /* Workaround for MSVC */
--- a/src/api-misc.c
+++ b/src/api-misc.c
@@ -37,7 +37,7 @@ int mdbx_dbi_sequence(MDBX_txn *txn, MDBX_dbi dbi, uint64_t *result, uint64_t in
    return LOG_IFERR(rc);

  if (unlikely(txn->dbi_state[dbi] & DBI_STALE)) {
-    rc = tbl_fetch(txn, dbi);
+    rc = tbl_refresh_absent2baddbi(txn, dbi);
    if (unlikely(rc != MDBX_SUCCESS))
      return LOG_IFERR(rc);
  }
@@ -146,8 +146,7 @@ __cold const char *mdbx_liberr2str(int errnum) {
      " or Operation system not supported such operations",
      "MDBX_INCOMPATIBLE: Environment or database is not compatible"
      " with the requested operation or the specified flags",
-      "MDBX_BAD_RSLOT: Invalid reuse of reader locktable slot,"
-      " e.g. read-transaction already run for current thread",
+      "MDBX_BAD_RSLOT: Reader locktable slot was unexpectly reused or cleared by an enemy thread",
      "MDBX_BAD_TXN: Transaction is not valid for requested operation,"
      " e.g. had errored and be must aborted, has a child, or is invalid",
      "MDBX_BAD_VALSIZE: Invalid size or alignment of key or data"
--- a/src/api-txn.c
+++ b/src/api-txn.c
@@ -7,8 +7,7 @@
 /* LY: avoid tsan-trap by txn, mm_last_pg and geo.first_unallocated */
 __attribute__((__no_sanitize_thread__, __noinline__))
 #endif
-int mdbx_txn_straggler(const MDBX_txn *txn, int *percent)
-{
+int mdbx_txn_straggler(const MDBX_txn *txn, int *percent) {
  int rc = check_txn(txn, MDBX_TXN_BLOCKED - MDBX_TXN_PARKED);
  if (likely(rc == MDBX_SUCCESS))
    rc = check_env(txn->env, true);
--- a/src/atomics-ops.h
+++ b/src/atomics-ops.h
@@ -7,6 +7,33 @@

 #ifndef __cplusplus

+MDBX_MAYBE_UNUSED static __always_inline void atomic_yield(void) {
+#if defined(_WIN32) || defined(_WIN64)
+  YieldProcessor();
+#elif defined(__ia32__) || defined(__e2k__)
+  __builtin_ia32_pause();
+#elif defined(__ia64__)
+#if defined(__HP_cc__) || defined(__HP_aCC__)
+  _Asm_hint(_HINT_PAUSE);
+#else
+  __asm__ __volatile__("hint @pause");
+#endif
+#elif defined(__aarch64__) || (defined(__ARM_ARCH) && __ARM_ARCH > 6) || defined(__ARM_ARCH_6K__)
+#ifdef __CC_ARM
+  __yield();
+#else
+  __asm__ __volatile__("yield");
+#endif
+#elif (defined(__mips64) || defined(__mips64__)) && defined(__mips_isa_rev) && __mips_isa_rev >= 2
+  __asm__ __volatile__("pause");
+#elif defined(__mips) || defined(__mips__) || defined(__mips64) || defined(__mips64__) || defined(_M_MRX000) ||        \
+    defined(_MIPS_) || defined(__MWERKS__) || defined(__sgi)
+  __asm__ __volatile__(".word 0x00000140");
+#else
+  osal_yield();
+#endif
+}
+
 #ifdef MDBX_HAVE_C11ATOMICS
 #define osal_memory_fence(order, write) atomic_thread_fence((write) ? mo_c11_store(order) : mo_c11_load(order))
 #else /* MDBX_HAVE_C11ATOMICS */
@@ -115,8 +142,7 @@ MDBX_MAYBE_UNUSED static
 #if MDBX_64BIT_ATOMIC
    __always_inline
 #endif /* MDBX_64BIT_ATOMIC */
-        uint64_t
-        atomic_load64(const volatile mdbx_atomic_uint64_t *p, enum mdbx_memory_order order) {
+        uint64_t atomic_load64(const volatile mdbx_atomic_uint64_t *p, enum mdbx_memory_order order) {
  STATIC_ASSERT(sizeof(mdbx_atomic_uint64_t) == 8);
 #if MDBX_64BIT_ATOMIC
 #ifdef MDBX_HAVE_C11ATOMICS
@@ -144,38 +170,12 @@ MDBX_MAYBE_UNUSED static
    if (likely(value == again))
      return value;
    value = again;
+    atomic_yield();
  }
 #endif /* !MDBX_64BIT_ATOMIC */
 }
 #endif /* atomic_load64 */

-MDBX_MAYBE_UNUSED static __always_inline void atomic_yield(void) {
-#if defined(_WIN32) || defined(_WIN64)
-  YieldProcessor();
-#elif defined(__ia32__) || defined(__e2k__)
-  __builtin_ia32_pause();
-#elif defined(__ia64__)
-#if defined(__HP_cc__) || defined(__HP_aCC__)
-  _Asm_hint(_HINT_PAUSE);
-#else
-  __asm__ __volatile__("hint @pause");
-#endif
-#elif defined(__aarch64__) || (defined(__ARM_ARCH) && __ARM_ARCH > 6) || defined(__ARM_ARCH_6K__)
-#ifdef __CC_ARM
-  __yield();
-#else
-  __asm__ __volatile__("yield");
-#endif
-#elif (defined(__mips64) || defined(__mips64__)) && defined(__mips_isa_rev) && __mips_isa_rev >= 2
-  __asm__ __volatile__("pause");
-#elif defined(__mips) || defined(__mips__) || defined(__mips64) || defined(__mips64__) || defined(_M_MRX000) ||        \
-    defined(_MIPS_) || defined(__MWERKS__) || defined(__sgi)
-  __asm__ __volatile__(".word 0x00000140");
-#else
-  osal_yield();
-#endif
-}
-
 #if MDBX_64BIT_CAS
 MDBX_MAYBE_UNUSED static __always_inline bool atomic_cas64(mdbx_atomic_uint64_t *p, uint64_t c, uint64_t v) {
 #ifdef MDBX_HAVE_C11ATOMICS
@@ -312,10 +312,11 @@ MDBX_MAYBE_UNUSED static __always_inline void safe64_write(mdbx_atomic_uint64_t

 MDBX_MAYBE_UNUSED static __always_inline uint64_t safe64_read(const mdbx_atomic_uint64_t *p) {
  jitter4testing(true);
-  uint64_t v;
-  do
+  uint64_t v = atomic_load64(p, mo_AcquireRelease);
+  while (!MDBX_64BIT_ATOMIC && unlikely(v != p->weak)) {
+    atomic_yield();
    v = atomic_load64(p, mo_AcquireRelease);
-  while (!MDBX_64BIT_ATOMIC && unlikely(v != p->weak));
+  }
  return v;
 }

@@ -353,8 +354,7 @@ MDBX_MAYBE_UNUSED static
 #if MDBX_64BIT_ATOMIC
    __always_inline
 #endif /* MDBX_64BIT_ATOMIC */
-    void
-    safe64_inc(mdbx_atomic_uint64_t *p, const uint64_t v) {
+    void safe64_inc(mdbx_atomic_uint64_t *p, const uint64_t v) {
  assert(v > 0);
  safe64_update(p, safe64_read(p) + v);
 }
--- a/src/chk.c
+++ b/src/chk.c
@@ -196,6 +196,49 @@ __cold static MDBX_chk_line_t *chk_print_size(MDBX_chk_line_t *line, const char
  return line;
 }

+__cold static MDBX_chk_line_t *chk_print_ratio(MDBX_chk_line_t *line, size_t numerator, size_t denominator,
+                                               unsigned precision) {
+  if (line) {
+    ratio2digits_buffer_t buffer;
+    line = chk_puts(line, ratio2digits(numerator, denominator, &buffer, precision));
+  }
+  return line;
+}
+
+__cold static MDBX_chk_line_t *chk_print_percent(MDBX_chk_line_t *line, const char *triplet, size_t value, size_t whole,
+                                                 const char *unit) {
+  if (line) {
+    const char *s1 = triplet;
+    const char *s2 = s1 + strlen(s1) + 1;
+    const char *s3 = s2 + strlen(s2) + 1;
+    ratio2digits_buffer_t buffer;
+    line = chk_print(line, "%s %" PRIuSIZE "%s%s (%s%%%s)%s", s1, value, unit, &"s"[*unit == 0 || value == 1],
+                     ratio2percent(value, whole, &buffer), s2, s3);
+  }
+  return line;
+}
+
+__cold static MDBX_chk_line_t *chk_print_pages_percent(MDBX_chk_line_t *line, const char *triplet, size_t pages,
+                                                       size_t whole) {
+  return chk_print_percent(line, triplet, pages, whole, " page");
+}
+
+__cold static MDBX_chk_line_t *chk_print_bytes_percent(MDBX_chk_line_t *line, const char *triplet, size_t pages,
+                                                       size_t whole) {
+  return chk_print_percent(line, triplet, pages, whole, " byte");
+}
+
+__cold static MDBX_chk_line_t *chk_print_pages_percent_bb(MDBX_chk_line_t *line, const char *prefix, size_t pages,
+                                                          size_t backed, size_t boundary) {
+  if (line) {
+    ratio2digits_buffer_t buffer_backed, buffer_boundary;
+    line =
+        chk_print(line, "%s %" PRIuSIZE " page%s (%s%% of backed, %s%% of boundary)", prefix, pages, &"s"[pages == 1],
+                  ratio2percent(pages, backed, &buffer_backed), ratio2percent(pages, boundary, &buffer_boundary));
+  }
+  return line;
+}
+
 __cold static int chk_error_rc(MDBX_chk_scope_t *const scope, int err, const char *subj) {
  MDBX_chk_line_t *line = chk_line_begin(scope, MDBX_chk_error);
  if (line)
@@ -568,11 +611,23 @@ static void histogram_acc(const size_t n, struct MDBX_chk_histogram *p) {

 __cold static MDBX_chk_line_t *histogram_dist(MDBX_chk_line_t *line, const struct MDBX_chk_histogram *histogram,
                                              const char *prefix, const char *first, bool amount) {
+  /* https://en.wikipedia.org/wiki/Multiplication_sign */
+#if defined(unix) || defined(linux) || defined(__unix__) || defined(__unix) || defined(__linux__) ||                   \
+    defined(__APPLE__) || defined(__MACH__) || defined(_DARWIN_C_SOURCE)
+#define UNICODE_MULSIGN_STR "×"
+#define UNICODE_MULSIGN_FMT "s"
+#elif defined(_WIN32) || defined(_WIN64)
+#define UNICODE_MULSIGN_STR L"\u00d7"
+#define UNICODE_MULSIGN_FMT "ls"
+#else
+#define UNICODE_MULSIGN_STR "*"
+#define UNICODE_MULSIGN_FMT "s"
+#endif
  line = chk_print(line, "%s:", prefix);
  const char *comma = "";
  const size_t first_val = amount ? histogram->ones : histogram->pad;
  if (first_val) {
-    chk_print(line, " %s=%" PRIuSIZE, first, first_val);
+    chk_print(line, " %s%" UNICODE_MULSIGN_FMT "%" PRIuSIZE, first, UNICODE_MULSIGN_STR, first_val);
    comma = ",";
  }
  for (size_t n = 0; n < ARRAY_LENGTH(histogram->ranges); ++n)
@@ -580,7 +635,8 @@ __cold static MDBX_chk_line_t *histogram_dist(MDBX_chk_line_t *line, const struc
      chk_print(line, "%s %" PRIuSIZE, comma, histogram->ranges[n].begin);
      if (histogram->ranges[n].begin != histogram->ranges[n].end - 1)
        chk_print(line, "-%" PRIuSIZE, histogram->ranges[n].end - 1);
-      line = chk_print(line, "=%" PRIuSIZE, amount ? histogram->ranges[n].amount : histogram->ranges[n].count);
+      line = chk_print(line, "%" UNICODE_MULSIGN_FMT "%" PRIuSIZE, UNICODE_MULSIGN_STR,
+                       amount ? histogram->ranges[n].amount : histogram->ranges[n].count);
      comma = ",";
    }
  return line;
@@ -668,7 +724,7 @@ __cold static void chk_verbose_meta(MDBX_chk_scope_t *const scope, const unsigne
    line = chk_print(line, " txn#%" PRIaTXN ", ", meta_txnid);
    if (chk->envinfo.mi_bootid.meta[num].x | chk->envinfo.mi_bootid.meta[num].y)
      line = chk_print(line, "boot-id %" PRIx64 "-%" PRIx64 " (%s)", chk->envinfo.mi_bootid.meta[num].x,
-                       chk->envinfo.mi_bootid.meta[num].y, bootid_match ? "live" : "not match");
+                       chk->envinfo.mi_bootid.meta[num].y, bootid_match ? "live" : "dissimilar");
    else
      line = chk_puts(line, "no boot-id");

@@ -701,7 +757,8 @@ __cold static int chk_pgvisitor(const size_t pgno, const unsigned npages, void *
    chk_scope_issue(scope, "too deeply %u, page %zu, parent %zu", deep, pgno, parent_pgno);
    return MDBX_CORRUPTED /* avoid infinite loop/recursion */;
  }
-  histogram_acc(deep, &tbl->histogram.deep);
+  if (pagetype != page_large)
+    histogram_acc(deep, &tbl->histogram.height);
  usr->result.processed_pages += npages;
  const size_t page_bytes = payload_bytes + header_bytes + unused_bytes;

@@ -722,27 +779,28 @@ __cold static int chk_pgvisitor(const size_t pgno, const unsigned npages, void *

  const char *pagetype_caption;
  bool branch = false;
-  struct MDBX_chk_histogram *filling = nullptr;
+  struct MDBX_chk_histogram *density = nullptr;
  switch (pagetype) {
  default:
    chk_object_issue(scope, "page", pgno, "unknown page-type", "type %u, deep %i, parent %zu", (unsigned)pagetype, deep,
                     parent_pgno);
    pagetype_caption = "unknown";
-    tbl->pages.other += npages;
+    tbl->pages.broken += npages;
    break;
  case page_broken:
    assert(page_err != MDBX_SUCCESS);
    pagetype_caption = "broken";
-    tbl->pages.other += npages;
+    tbl->pages.broken += npages;
    break;
  case page_sub_broken:
    assert(page_err != MDBX_SUCCESS);
    pagetype_caption = "broken-subpage";
-    tbl->pages.other += npages;
+    tbl->pages.broken += npages;
    break;
  case page_large:
    pagetype_caption = "large";
    histogram_acc(npages, &tbl->histogram.large_pages);
+    density = &tbl->histogram.large_or_nested_density;
    if (tbl->flags & MDBX_DUPSORT)
      chk_object_issue(scope, "page", pgno, "unexpected", "type %u, table %s flags 0x%x, deep %i, parent %zu",
                       (unsigned)pagetype, chk_v2a(chk, &tbl->name), tbl->flags, deep, parent_pgno);
@@ -752,11 +810,11 @@ __cold static int chk_pgvisitor(const size_t pgno, const unsigned npages, void *
    if (!nested) {
      pagetype_caption = "branch";
      tbl->pages.branch += 1;
-      filling = &tbl->histogram.tree_filling;
+      density = &tbl->histogram.tree_density;
    } else {
      pagetype_caption = "nested-branch";
      tbl->pages.nested_branch += 1;
-      filling = &tbl->histogram.nested_tree_filling;
+      density = &tbl->histogram.large_or_nested_density;
    }
    break;
  case page_dupfix_leaf:
@@ -769,16 +827,16 @@ __cold static int chk_pgvisitor(const size_t pgno, const unsigned npages, void *
    if (!nested) {
      pagetype_caption = "leaf";
      tbl->pages.leaf += 1;
-      filling = &tbl->histogram.tree_filling;
+      density = &tbl->histogram.tree_density;
      if (height != tbl_info->internal->height)
        chk_object_issue(scope, "page", pgno, "wrong tree height", "actual %i != %i table %s, parent %zu", height,
                         tbl_info->internal->height, chk_v2a(chk, &tbl->name), parent_pgno);
    } else {
      pagetype_caption = (pagetype == page_leaf) ? "nested-leaf" : "nested-leaf-dupfix";
      tbl->pages.nested_leaf += 1;
-      filling = &tbl->histogram.nested_tree_filling;
+      density = &tbl->histogram.large_or_nested_density;
      if (chk->last_nested != nested) {
-        histogram_acc(height, &tbl->histogram.nested_tree);
+        histogram_acc(height, &tbl->histogram.nested_height);
        chk->last_nested = nested;
      }
      if (height != nested->height)
@@ -794,12 +852,12 @@ __cold static int chk_pgvisitor(const size_t pgno, const unsigned npages, void *
      chk_object_issue(scope, "page", pgno, "unexpected", "type %u, table %s flags 0x%x, deep %i, parent %zu",
                       (unsigned)pagetype, chk_v2a(chk, &tbl->name), tbl->flags, deep, parent_pgno);
    else
-      filling = &tbl->histogram.nested_tree_filling;
+      density = &tbl->histogram.large_or_nested_density;
    break;
  }

-  if (filling)
-    histogram_acc((page_size - unused_bytes) * 100 / page_size, filling);
+  if (density)
+    histogram_acc((page_size - unused_bytes) * 100 / page_size, density);

  if (npages) {
    if (tbl->cookie) {
@@ -914,7 +972,7 @@ __cold static int chk_tree(MDBX_chk_scope_t *const scope) {
    total.lost_bytes += tbl->lost_bytes;
    total.pages.all += tbl->pages.all;
    total.pages.empty += tbl->pages.empty;
-    total.pages.other += tbl->pages.other;
+    total.pages.broken += tbl->pages.broken;
    total.pages.branch += tbl->pages.branch;
    total.pages.leaf += tbl->pages.leaf;
    total.pages.nested_branch += tbl->pages.nested_branch;
@@ -934,53 +992,55 @@ __cold static int chk_tree(MDBX_chk_scope_t *const scope) {
  if (scope->verbosity > MDBX_chk_info) {
    for (size_t i = 0; i < ARRAY_LENGTH(chk->table) && chk->table[i]; ++i) {
      MDBX_chk_table_t *const tbl = chk->table[i];
-      MDBX_chk_scope_t *inner = chk_scope_push(scope, 0, "tree %s:", chk_v2a(chk, &tbl->name));
-      if (tbl->pages.all == 0)
-        chk_line_end(chk_print(chk_line_begin(inner, MDBX_chk_resolution), "empty"));
-      else {
+      MDBX_chk_scope_t *inner =
+          chk_scope_push(scope, 0, (tbl->pages.all ? "b-tree %s, subtotal %" PRIuSIZE " pages:" : "b-tree %s: empty"),
+                         chk_v2a(chk, &tbl->name), tbl->pages.all);
+      if (tbl->pages.all) {
        MDBX_chk_line_t *line = chk_line_begin(inner, MDBX_chk_info);
        if (line) {
-          line = chk_print(line, "page usage: subtotal %" PRIuSIZE, tbl->pages.all);
-          const size_t branch_pages = tbl->pages.branch + tbl->pages.nested_branch;
-          const size_t leaf_pages = tbl->pages.leaf + tbl->pages.nested_leaf + tbl->pages.nested_subleaf;
-          if (tbl->pages.other)
-            line = chk_print(line, ", other %" PRIuSIZE, tbl->pages.other);
-          if (tbl->pages.other == 0 || (branch_pages | leaf_pages | tbl->histogram.large_pages.count) != 0) {
-            line = chk_print(line, ", branch %" PRIuSIZE ", leaf %" PRIuSIZE, branch_pages, leaf_pages);
+          line = chk_puts(line, "pages composition: ");
+          if (tbl->pages.broken)
+            line = chk_print(line, "broken %" PRIuSIZE ", ", tbl->pages.broken);
+          if (tbl->pages.broken != tbl->pages.all) {
+            line = chk_print(line, "branch %" PRIuSIZE ", leaf %" PRIuSIZE, tbl->pages.branch, tbl->pages.leaf);
+            if (tbl->pages.nested_subleaf || (tbl->flags & MDBX_DUPSORT) != 0)
+              line = chk_print(line, ", subleaf %" PRIuSIZE, tbl->pages.nested_subleaf);
+            if (tbl->pages.nested_branch || (tbl->flags & MDBX_DUPSORT) != 0)
+              line = chk_print(line, ", nested-branch %" PRIuSIZE, tbl->pages.nested_branch);
+            if (tbl->pages.nested_leaf || (tbl->flags & MDBX_DUPSORT) != 0)
+              line = chk_print(line, ", nested-leaf %" PRIuSIZE, tbl->pages.nested_leaf);
            if (tbl->histogram.large_pages.count || (tbl->flags & MDBX_DUPSORT) == 0) {
              line = chk_print(line, ", large %" PRIuSIZE, tbl->histogram.large_pages.count);
              if (tbl->histogram.large_pages.amount | tbl->histogram.large_pages.count)
                line = histogram_print(inner, line, &tbl->histogram.large_pages, " amount", "single", true);
            }
-          }
-          line = histogram_dist(chk_line_feed(line), &tbl->histogram.deep, "tree deep density", "1", false);
-          if (tbl != &chk->table_gc && tbl->histogram.nested_tree.count) {
-            line = chk_print(chk_line_feed(line), "nested tree(s) %" PRIuSIZE, tbl->histogram.nested_tree.count);
-            line = histogram_dist(line, &tbl->histogram.nested_tree, " density", "1", false);
-            line = chk_print(chk_line_feed(line),
-                             "nested tree(s) pages %" PRIuSIZE ": branch %" PRIuSIZE ", leaf %" PRIuSIZE
-                             ", subleaf %" PRIuSIZE,
-                             tbl->pages.nested_branch + tbl->pages.nested_leaf, tbl->pages.nested_branch,
-                             tbl->pages.nested_leaf, tbl->pages.nested_subleaf);
-          }
+            line = histogram_dist(chk_line_feed(line), &tbl->histogram.height, "tree levels", "1", false);
+            if ((tbl->flags & MDBX_DUPSORT) != 0 || (tbl->histogram.nested_height.count && tbl != &chk->table_gc)) {
+              line = chk_print(chk_line_feed(line),
+                               "nested tree(s): quantity %" PRIuSIZE ", subtotal pages %" PRIuSIZE ", ",
+                               tbl->histogram.nested_height.count, tbl->pages.nested_branch + tbl->pages.nested_leaf);
+              if (tbl != &chk->table_gc && tbl->histogram.nested_height.count)
+                line = histogram_dist(line, &tbl->histogram.nested_height, "levels", "1", false);
+            }
+            line = chk_line_feed(line);

-          const size_t bytes = pgno2bytes(env, tbl->pages.all);
-          line =
-              chk_print(chk_line_feed(line),
-                        "page filling: subtotal %" PRIuSIZE " bytes (%.1f%%), payload %" PRIuSIZE
-                        " (%.1f%%), unused %" PRIuSIZE " (%.1f%%)",
-                        bytes, bytes * 100.0 / total_page_bytes, tbl->payload_bytes, tbl->payload_bytes * 100.0 / bytes,
-                        bytes - tbl->payload_bytes, (bytes - tbl->payload_bytes) * 100.0 / bytes);
-          if (tbl->pages.empty)
-            line = chk_print(line, ", %" PRIuSIZE " empty pages", tbl->pages.empty);
-          if (tbl->lost_bytes)
-            line = chk_print(line, ", %" PRIuSIZE " bytes lost", tbl->lost_bytes);
+            const size_t bytes = pgno2bytes(env, tbl->pages.all);
+            line = chk_print_bytes_percent(line, "pages density: subtotal\0\0", bytes, total_page_bytes);
+            line = chk_print_percent(line, ", payload\0\0", tbl->payload_bytes, bytes, "");
+            line = chk_print_percent(line, ", unused\0\0", bytes - tbl->payload_bytes, bytes, "");
+            if (tbl->pages.empty)
+              line = chk_print(line, ", %" PRIuSIZE " empty pages", tbl->pages.empty);
+            if (tbl->lost_bytes)
+              line = chk_print(line, ", %" PRIuSIZE " bytes lost", tbl->lost_bytes);

-          line =
-              histogram_dist(chk_line_feed(line), &tbl->histogram.tree_filling, "tree %-filling density", "1", false);
-          if (tbl->histogram.nested_tree_filling.count)
-            line = histogram_dist(chk_line_feed(line), &tbl->histogram.nested_tree_filling,
-                                  "nested tree(s) %-filling density", "1", false);
+            line = histogram_dist(chk_line_feed(line), &tbl->histogram.tree_density, "pages %-density distribution",
+                                  "1", false);
+            if (tbl->histogram.large_or_nested_density.count)
+              line = histogram_dist(chk_line_feed(line), &tbl->histogram.large_or_nested_density,
+                                    (tbl->flags & MDBX_DUPSORT) ? "nested %-density distribution"
+                                                                : "large pages %-density distribution",
+                                    "1", false);
+          }
          chk_line_end(line);
        }
      }
@@ -989,14 +1049,11 @@ __cold static int chk_tree(MDBX_chk_scope_t *const scope) {
  }

  MDBX_chk_line_t *line = chk_line_begin(scope, MDBX_chk_resolution);
-  line = chk_print(line,
-                   "summary: total %" PRIuSIZE " bytes, payload %" PRIuSIZE " (%.1f%%), unused %" PRIuSIZE " (%.1f%%),"
-                   " average fill %.1f%%",
-                   total_page_bytes, usr->result.total_payload_bytes,
-                   usr->result.total_payload_bytes * 100.0 / total_page_bytes,
-                   total_page_bytes - usr->result.total_payload_bytes,
-                   (total_page_bytes - usr->result.total_payload_bytes) * 100.0 / total_page_bytes,
-                   usr->result.total_payload_bytes * 100.0 / total_page_bytes);
+  line = chk_print(line, "summary: total %" PRIuSIZE " bytes", total_page_bytes);
+  line =
+      chk_print_percent(line, ", payload\0 average density\0", usr->result.total_payload_bytes, total_page_bytes, "");
+  line = chk_print_percent(line, ", unused\0 average sparsity\0", total_page_bytes - usr->result.total_payload_bytes,
+                           total_page_bytes, "");
  if (total.pages.empty)
    line = chk_print(line, ", %" PRIuSIZE " empty pages", total.pages.empty);
  if (total.lost_bytes)
@@ -1285,15 +1342,16 @@ bailout:
    if (handler) {
      if (record_count) {
        MDBX_chk_line_t *line = chk_line_begin(scope, MDBX_chk_info);
-        line = histogram_dist(line, &tbl->histogram.key_len, "key length density", "0/1", false);
+        line = histogram_dist(line, &tbl->histogram.key_len, "key length distribution", "0/1", false);
        chk_line_feed(line);
-        line = histogram_dist(line, &tbl->histogram.val_len, "value length density", "0/1", false);
+        line = histogram_dist(line, &tbl->histogram.val_len, "value length distribution", "0/1", false);
        if (tbl->histogram.multival.amount) {
          chk_line_feed(line);
-          line = histogram_dist(line, &tbl->histogram.multival, "number of multi-values density", "single", false);
+          line = histogram_dist(line, &tbl->histogram.multival, "number of multi-values distribution", "single", false);
          chk_line_feed(line);
-          line = chk_print(line, "number of keys %" PRIuSIZE ", average values per key %.1f",
-                           tbl->histogram.multival.count, record_count / (double)tbl->histogram.multival.count);
+          line =
+              chk_print(line, "number of keys %" PRIuSIZE ", average values per key ", tbl->histogram.multival.count);
+          line = chk_print_ratio(line, record_count, tbl->histogram.multival.count, 1);
        }
        chk_line_end(line);
      }
@@ -1302,16 +1360,20 @@ bailout:
      if (chk->cb->table_conclude)
        err = chk->cb->table_conclude(usr, tbl, cursor, err);
      MDBX_chk_line_t *line = chk_line_begin(scope, MDBX_chk_resolution);
-      line = chk_print(line, "summary: %" PRIuSIZE " records,", record_count);
-      if (dups || (tbl->flags & (MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_REVERSEDUP | MDBX_INTEGERDUP)))
-        line = chk_print(line, " %" PRIuSIZE " dups,", dups);
-      if (sub_databases || dbi == MAIN_DBI)
-        line = chk_print(line, " %" PRIuSIZE " tables,", sub_databases);
-      line = chk_print(line,
-                       " %" PRIuSIZE " key's bytes,"
-                       " %" PRIuSIZE " data's bytes,"
-                       " %" PRIuSIZE " problem(s)",
-                       tbl->histogram.key_len.amount, tbl->histogram.val_len.amount, scope->subtotal_issues);
+      if (record_count | tbl->histogram.key_len.amount | tbl->histogram.val_len.amount | scope->subtotal_issues) {
+        line = chk_print(line, "summary: %" PRIuSIZE " records,", record_count);
+        if (dups || (tbl->flags & (MDBX_DUPSORT | MDBX_DUPFIXED | MDBX_REVERSEDUP | MDBX_INTEGERDUP)))
+          line = chk_print(line, " %" PRIuSIZE " dups,", dups);
+        if (sub_databases || dbi == MAIN_DBI)
+          line = chk_print(line, " %" PRIuSIZE " tables,", sub_databases);
+        line = chk_print(line,
+                         " %" PRIuSIZE " key's bytes,"
+                         " %" PRIuSIZE " data's bytes,"
+                         " %" PRIuSIZE " problem(s)",
+                         tbl->histogram.key_len.amount, tbl->histogram.val_len.amount, scope->subtotal_issues);
+      } else {
+        line = chk_puts(line, "empty");
+      }
      chk_line_end(chk_flush(line));
    }

@@ -1405,7 +1467,7 @@ __cold static int chk_handle_gc(MDBX_chk_scope_t *const scope, MDBX_chk_table_t
                         iptr[i + span] == (MDBX_PNL_ASCENDING ? pgno_add(pgno, span) : pgno_sub(pgno, span));
               ++span)
            ;
-          histogram_acc(span, &tbl->histogram.nested_tree);
+          histogram_acc(span, &tbl->histogram.nested_height);
          MDBX_chk_line_t *line = chk_line_begin(scope, MDBX_chk_extra);
          if (line) {
            if (span > 1)
@@ -1429,7 +1491,7 @@ __cold static int env_chk(MDBX_chk_scope_t *const scope) {
  MDBX_chk_context_t *const usr = chk->usr;
  MDBX_env *const env = usr->env;
  MDBX_txn *const txn = usr->txn;
-  int err = env_info(env, txn, &chk->envinfo, sizeof(chk->envinfo), &chk->troika);
+  int err = env_info(env, txn, &chk->envinfo, &chk->troika);
  if (unlikely(err))
    return chk_error_rc(scope, err, "env_info");

@@ -1449,9 +1511,11 @@ __cold static int env_chk(MDBX_chk_scope_t *const scope) {
    line = chk_puts(line, "is unavailable");
  chk_line_end(line);

-  err = osal_filesize(env->lazy_fd, &env->dxb_mmap.filesize);
-  if (unlikely(err))
-    return chk_error_rc(scope, err, "osal_filesize");
+  line = chk_print_size(chk_line_begin(scope, MDBX_chk_verbose), "system unified page cache block ",
+                        chk->envinfo.mi_sys_upcblk, "");
+  chk_line_end(line);
+
+  env->dxb_mmap.filesize = chk->envinfo.mi_dxb_fsize;

  //--------------------------------------------------------------------------

@@ -1503,11 +1567,13 @@ __cold static int env_chk(MDBX_chk_scope_t *const scope) {
        usr->result.backed_pages = (size_t)dxbfile_pages;
    }

-    line = chk_line_feed(chk_print(chk_line_begin(inner, MDBX_chk_info),
-                                   "pagesize %u (%u system), max keysize %u..%u"
-                                   ", max readers %u",
+    line = chk_line_feed(chk_print(chk_line_begin(inner, MDBX_chk_info), "pagesize %u (%u system), max keysize %u..%u",
                                   env->ps, globals.sys_pagesize, mdbx_env_get_maxkeysize_ex(env, MDBX_DUPSORT),
-                                   mdbx_env_get_maxkeysize_ex(env, MDBX_DB_DEFAULTS), env->max_readers));
+                                   mdbx_env_get_maxkeysize_ex(env, MDBX_DB_DEFAULTS)));
+    if ((env->flags & MDBX_EXCLUSIVE) == 0 && env->lck_mmap.lck) {
+      line = chk_line_feed(chk_print(chk_line_begin(inner, MDBX_chk_info), "currently %u readers of %u maximum",
+                                     atomic_load32(&env->lck_mmap.lck->rdt_length, mo_Relaxed), env->max_readers));
+    }
    line = chk_line_feed(chk_print_size(line, "mapsize ", env->dxb_mmap.current, nullptr));
    if (txn->geo.lower == txn->geo.upper)
      line = chk_print_size(line, "fixed datafile: ", chk->envinfo.mi_geo.current, nullptr);
@@ -1530,6 +1596,19 @@ __cold static int env_chk(MDBX_chk_scope_t *const scope) {
      chk_line_end(chk_print(line, " > until it will be closed or reopened in read-write mode."));
    }
 #endif /* Windows || Debug */
+    line = chk_print_size(chk_line_begin(scope, MDBX_chk_verbose), "filesystem: io-block ", chk->envinfo.mi_sys_ioblk,
+                          ", space allocated for the dxb-file ");
+    if (chk->envinfo.mi_dxb_fallocated == chk->envinfo.mi_geo.current) {
+      line = chk_puts(line, "exactly");
+    } else {
+      line = chk_print_size(
+          line, (chk->envinfo.mi_dxb_fallocated > chk->envinfo.mi_geo.current) ? "with excess " : "partially ",
+          chk->envinfo.mi_dxb_fallocated, " ");
+      ratio2digits_buffer_t buffer;
+      line =
+          chk_print(line, "%s%%", ratio2percent(chk->envinfo.mi_dxb_fallocated, chk->envinfo.mi_geo.current, &buffer));
+    }
+    chk_line_end(line);
    chk_verbose_meta(inner, 0);
    chk_verbose_meta(inner, 1);
    chk_verbose_meta(inner, 2);
@@ -1628,7 +1707,7 @@ __cold static int env_chk(MDBX_chk_scope_t *const scope) {
      err = chk_db(usr->scope, FREE_DBI, &chk->table_gc, chk_handle_gc);
    line = chk_line_begin(scope, MDBX_chk_info);
    if (line) {
-      histogram_print(scope, line, &chk->table_gc.histogram.nested_tree, "span(s)", "single", false);
+      histogram_print(scope, line, &chk->table_gc.histogram.nested_height, "span(s)", "single", false);
      chk_line_end(line);
    }
    if (usr->result.problems_gc == 0 && (chk->flags & MDBX_CHK_SKIP_BTREE_TRAVERSAL) == 0) {
@@ -1646,69 +1725,50 @@ __cold static int env_chk(MDBX_chk_scope_t *const scope) {
  //--------------------------------------------------------------------------

  err = chk_scope_begin(chk, 1, MDBX_chk_space, nullptr, nullptr, "Page allocation:");
-  const double percent_boundary_reciprocal = 100.0 / txn->geo.upper;
-  const double percent_backed_reciprocal = 100.0 / usr->result.backed_pages;
+  const size_t backed = usr->result.backed_pages;
+  const size_t boundary = txn->geo.upper;
  const size_t detained = usr->result.gc_pages - usr->result.reclaimable_pages;
-  const size_t available2boundary = txn->geo.upper - usr->result.alloc_pages + usr->result.reclaimable_pages;
-  const size_t available2backed = usr->result.backed_pages - usr->result.alloc_pages + usr->result.reclaimable_pages;
-  const size_t remained2boundary = txn->geo.upper - usr->result.alloc_pages;
-  const size_t remained2backed = usr->result.backed_pages - usr->result.alloc_pages;
+  const size_t available2boundary = boundary - usr->result.alloc_pages + usr->result.reclaimable_pages;
+  const size_t available2backed = backed - usr->result.alloc_pages + usr->result.reclaimable_pages;
+  const size_t remained2boundary = boundary - usr->result.alloc_pages;
+  const size_t remained2backed = backed - usr->result.alloc_pages;

  const size_t used = (chk->flags & MDBX_CHK_SKIP_BTREE_TRAVERSAL) ? usr->result.alloc_pages - usr->result.gc_pages
                                                                   : usr->result.processed_pages;

  line = chk_line_begin(usr->scope, MDBX_chk_info);
-  line = chk_print(line,
-                   "backed by file: %" PRIuSIZE " pages (%.1f%%)"
-                   ", %" PRIuSIZE " left to boundary (%.1f%%)",
-                   usr->result.backed_pages, usr->result.backed_pages * percent_boundary_reciprocal,
-                   txn->geo.upper - usr->result.backed_pages,
-                   (txn->geo.upper - usr->result.backed_pages) * percent_boundary_reciprocal);
+  line = chk_print_pages_percent(line, "backed by file:\0 of boundary\0", backed, boundary);
+  line = chk_print_pages_percent(line, ",\0\0 left to boundary", boundary - backed, boundary);
  line = chk_line_feed(line);

-  line = chk_print(line, "%s: %" PRIuSIZE " page(s), %.1f%% of backed, %.1f%% of boundary", "used", used,
-                   used * percent_backed_reciprocal, used * percent_boundary_reciprocal);
+  line = chk_print_pages_percent_bb(line, "used:", used, backed, boundary);
  line = chk_line_feed(line);

-  line = chk_print(line, "%s: %" PRIuSIZE " page(s) (%.1f%%) of backed, %" PRIuSIZE " to boundary (%.1f%% of boundary)",
-                   "remained", remained2backed, remained2backed * percent_backed_reciprocal, remained2boundary,
-                   remained2boundary * percent_boundary_reciprocal);
+  line = chk_print_pages_percent(line, "remained:\0\0 of backed", remained2backed, backed);
+  line = chk_print_pages_percent(line, ", left\0\0 to boundary", remained2boundary, boundary);
  line = chk_line_feed(line);

-  line =
-      chk_print(line,
-                "reclaimable: %" PRIuSIZE " (%.1f%% of backed, %.1f%% of boundary)"
-                ", GC %" PRIuSIZE " (%.1f%% of backed, %.1f%% of boundary)",
-                usr->result.reclaimable_pages, usr->result.reclaimable_pages * percent_backed_reciprocal,
-                usr->result.reclaimable_pages * percent_boundary_reciprocal, usr->result.gc_pages,
-                usr->result.gc_pages * percent_backed_reciprocal, usr->result.gc_pages * percent_boundary_reciprocal);
+  line = chk_print_pages_percent_bb(line, "reclaimable:", usr->result.reclaimable_pages, backed, boundary);
+  line = chk_print_pages_percent_bb(line, ", within GC", usr->result.gc_pages, backed, boundary);
  line = chk_line_feed(line);

-  line = chk_print(line,
-                   "detained by reader(s): %" PRIuSIZE " (%.1f%% of backed, %.1f%% of boundary)"
-                   ", %u reader(s), lag %" PRIi64,
-                   detained, detained * percent_backed_reciprocal, detained * percent_boundary_reciprocal,
-                   chk->envinfo.mi_numreaders, chk->envinfo.mi_recent_txnid - chk->envinfo.mi_latter_reader_txnid);
+  line = chk_print_pages_percent_bb(line, "detained by reader(s):", detained, backed, boundary);
+  line = chk_print(line, ", %u reader(s), lag %" PRIi64, chk->envinfo.mi_numreaders,
+                   chk->envinfo.mi_recent_txnid - chk->envinfo.mi_latter_reader_txnid);
  line = chk_line_feed(line);

-  line = chk_print(line, "%s: %" PRIuSIZE " page(s), %.1f%% of backed, %.1f%% of boundary", "allocated",
-                   usr->result.alloc_pages, usr->result.alloc_pages * percent_backed_reciprocal,
-                   usr->result.alloc_pages * percent_boundary_reciprocal);
+  line = chk_print_pages_percent_bb(line, "allocated:", usr->result.alloc_pages, backed, boundary);
  line = chk_line_feed(line);

-  line = chk_print(line, "%s: %" PRIuSIZE " page(s) (%.1f%%) of backed, %" PRIuSIZE " to boundary (%.1f%% of boundary)",
-                   "available", available2backed, available2backed * percent_backed_reciprocal, available2boundary,
-                   available2boundary * percent_boundary_reciprocal);
+  line = chk_print_pages_percent(line, "available:\0 of backed\0", available2backed, backed);
+  line = chk_print_pages_percent(line, ", left\0\0 to boundary", available2boundary, boundary);
  chk_line_end(line);

  line = chk_line_begin(usr->scope, MDBX_chk_resolution);
-  line = chk_print(line, "%s %" PRIaPGNO " pages", (txn->geo.upper == txn->geo.now) ? "total" : "upto", txn->geo.upper);
-  line = chk_print(line, ", backed %" PRIuSIZE " (%.1f%%)", usr->result.backed_pages,
-                   usr->result.backed_pages * percent_boundary_reciprocal);
-  line = chk_print(line, ", allocated %" PRIuSIZE " (%.1f%%)", usr->result.alloc_pages,
-                   usr->result.alloc_pages * percent_boundary_reciprocal);
-  line = chk_print(line, ", available %" PRIuSIZE " (%.1f%%)", available2boundary,
-                   available2boundary * percent_boundary_reciprocal);
+  line = chk_print(line, "%s %zu pages", (boundary == txn->geo.now) ? "total" : "upto", boundary);
+  line = chk_print_pages_percent(line, ", backed\0\0", backed, boundary);
+  line = chk_print_pages_percent(line, ", allocated\0\0", usr->result.alloc_pages, boundary);
+  line = chk_print_pages_percent(line, ", available\0\0", available2boundary, boundary);
  chk_line_end(line);
  chk_scope_restore(scope, err);

--- a/src/cogs.h
+++ b/src/cogs.h
@@ -200,15 +200,21 @@ static inline bool check_table_flags(unsigned flags) {
  }
 }

-static inline int tbl_setup_ifneed(const MDBX_env *env, volatile kvx_t *const kvx, const tree_t *const db) {
+MDBX_MAYBE_UNUSED static inline int tbl_setup_ifneed(const MDBX_env *env, volatile kvx_t *const kvx,
+                                                     const tree_t *const db) {
  return likely(kvx->clc.v.lmax) ? MDBX_SUCCESS : tbl_setup(env, kvx, db);
 }

+MDBX_MAYBE_UNUSED static inline int tbl_refresh_absent2baddbi(MDBX_txn *txn, size_t dbi) {
+  int rc = tbl_refresh(txn, dbi);
+  return likely(rc != MDBX_NOTFOUND) ? rc : MDBX_BAD_DBI;
+}
+
 /*----------------------------------------------------------------------------*/

 MDBX_NOTHROW_PURE_FUNCTION static inline size_t pgno2bytes(const MDBX_env *env, size_t pgno) {
  eASSERT(env, (1u << env->ps2ln) == env->ps);
-  return ((size_t)pgno) << env->ps2ln;
+  return pgno << env->ps2ln;
 }

 MDBX_NOTHROW_PURE_FUNCTION static inline page_t *pgno2page(const MDBX_env *env, size_t pgno) {
@@ -286,7 +292,8 @@ MDBX_NOTHROW_PURE_FUNCTION static inline const page_t *payload2page(const void *
  return container_of(data, page_t, entries);
 }

-MDBX_NOTHROW_PURE_FUNCTION static inline const page_t *ptr2page(const MDBX_env *env, const void *ptr) {
+MDBX_NOTHROW_PURE_FUNCTION MDBX_MAYBE_UNUSED static inline const page_t *ptr2page(const MDBX_env *env,
+                                                                                  const void *ptr) {
  eASSERT(env,
          ptr_dist(ptr, env->dxb_mmap.base) >= 0 && (size_t)ptr_dist(ptr, env->dxb_mmap.base) < env->dxb_mmap.limit);
  const uintptr_t mask = env->ps - 1;
@@ -504,9 +511,9 @@ static inline int check_txn_rw(const MDBX_txn *txn, int bad_bits) {
 }

 MDBX_NOTHROW_CONST_FUNCTION static inline txnid_t txn_basis_snapshot(const MDBX_txn *txn) {
-  STATIC_ASSERT((MDBX_TXN_RDONLY >> 17) == 1);
-  STATIC_ASSERT((xMDBX_TXNID_STEP >> (xMDBX_TXNID_STEP == 2)) == 1);
-  const txnid_t committed_txnid = txn->txnid + (xMDBX_TXNID_STEP >> (xMDBX_TXNID_STEP == 2)) - ((txn->flags >> 17) & 1);
+  STATIC_ASSERT(((MDBX_TXN_RDONLY >> ((xMDBX_TXNID_STEP == 2) ? 16 : 17)) & xMDBX_TXNID_STEP) == xMDBX_TXNID_STEP);
+  const txnid_t committed_txnid =
+      txn->txnid - xMDBX_TXNID_STEP + ((txn->flags >> ((xMDBX_TXNID_STEP == 2) ? 16 : 17)) & xMDBX_TXNID_STEP);
  tASSERT(txn, committed_txnid == ((txn->flags & MDBX_TXN_RDONLY) ? txn->txnid : txn->txnid - xMDBX_TXNID_STEP));
  return committed_txnid;
 }
--- a/src/config.h.in
+++ b/src/config.h.in
@@ -63,6 +63,11 @@

 #cmakedefine01 MDBX_USE_MINCORE

+#cmakedefine MDBX_USE_FALLOCATE_AUTO
+#ifndef MDBX_USE_FALLOCATE_AUTO
+#cmakedefine01 MDBX_USE_FALLOCATE
+#endif /* MDBX_USE_FALLOCATE */
+
 /* Build Info */
 #ifndef MDBX_BUILD_TIMESTAMP
 #cmakedefine MDBX_BUILD_TIMESTAMP "@MDBX_BUILD_TIMESTAMP@"
--- a/src/cursor.c
+++ b/src/cursor.c
@@ -293,7 +293,7 @@ static __always_inline int couple_init(cursor_couple_t *couple, const MDBX_txn *
  }

  if (unlikely(*dbi_state & DBI_STALE))
-    return tbl_fetch(couple->outer.txn, cursor_dbi(&couple->outer));
+    return tbl_refresh_absent2baddbi(couple->outer.txn, cursor_dbi(&couple->outer));

  return tbl_setup_ifneed(txn->env, kvx, tree);
 }
--- a/src/cursor.h
+++ b/src/cursor.h
@@ -236,7 +236,7 @@ enum cursor_checking {
 MDBX_INTERNAL int __must_check_result cursor_validate(const MDBX_cursor *mc);

 MDBX_MAYBE_UNUSED MDBX_NOTHROW_PURE_FUNCTION static inline size_t cursor_dbi(const MDBX_cursor *mc) {
-  cASSERT(mc, mc->txn && mc->txn->signature == txn_signature);
+  cASSERT(mc, mc->txn->signature == txn_signature);
  size_t dbi = mc->dbi_state - mc->txn->dbi_state;
  cASSERT(mc, dbi < mc->txn->env->n_dbi);
  return dbi;
--- a/src/dbi.c
+++ b/src/dbi.c
@@ -5,7 +5,7 @@

 #if MDBX_ENABLE_DBI_SPARSE
 size_t dbi_bitmap_ctz_fallback(const MDBX_txn *txn, intptr_t bmi) {
-  tASSERT(txn, bmi > 0);
+  tASSERT(txn, bmi != 0);
  bmi &= -bmi;
  if (sizeof(txn->dbi_sparse[0]) > 4) {
    static const uint8_t debruijn_ctz64[64] = {0,  1,  2,  53, 3,  7,  54, 27, 4,  38, 41, 8,  34, 55, 48, 28,
@@ -33,6 +33,23 @@ struct dbi_snap_result dbi_snap(const MDBX_env *env, const size_t dbi) {
  return r;
 }

+int dbi_gone(MDBX_txn *txn, const size_t dbi, const int rc) {
+  tASSERT(txn, txn->n_dbi > dbi && F_ISSET(txn->dbi_state[dbi], DBI_LINDO | DBI_VALID));
+  for (;;) {
+    unsigned state = txn->dbi_state[dbi];
+    txn->dbi_state[dbi] = DBI_OLDEN | DBI_LINDO;
+    if (state & (DBI_FRESH | DBI_CREAT))
+      return rc;
+    if (!txn->parent)
+      break;
+    txn = txn->parent;
+  }
+
+  /* TODO: FIXME */
+  txn->dbi_seqs[dbi] = 0;
+  return rc;
+}
+
 __noinline int dbi_import(MDBX_txn *txn, const size_t dbi) {
  const MDBX_env *const env = txn->env;
  if (dbi >= env->n_dbi || !env->dbs_flags[dbi])
@@ -266,8 +283,8 @@ int dbi_bind(MDBX_txn *txn, const size_t dbi, unsigned user_flags, MDBX_cmp_func
    else {
      if (txn->dbi_state[dbi] & DBI_STALE) {
        eASSERT(env, env->dbs_flags[dbi] & DB_VALID);
-        int err = tbl_fetch(txn, dbi);
-        if (unlikely(err == MDBX_SUCCESS))
+        int err = tbl_refresh(txn, dbi);
+        if (unlikely(err != MDBX_NOTFOUND))
          return err;
      }
      eASSERT(env, ((env->dbs_flags[dbi] ^ txn->dbs[dbi].flags) & DB_PERSISTENT_FLAGS) == 0);
@@ -325,8 +342,9 @@ static inline size_t dbi_namelen(const MDBX_val name) {
  return (name.iov_len > sizeof(defer_free_item_t)) ? name.iov_len : sizeof(defer_free_item_t);
 }

-static int dbi_open_locked(MDBX_txn *txn, unsigned user_flags, MDBX_dbi *dbi, MDBX_cmp_func *keycmp,
-                           MDBX_cmp_func *datacmp, MDBX_val name) {
+static int dbi_open_locked(MDBX_txn *txn, cursor_couple_t *maindb_cx, unsigned user_flags, MDBX_cmp_func *keycmp,
+                           MDBX_cmp_func *datacmp, MDBX_val name, const size_t fastpath_slot) {
+  int rc;
  MDBX_env *const env = txn->env;

  /* Cannot mix named table(s) with DUPSORT flags */
@@ -352,12 +370,12 @@ static int dbi_open_locked(MDBX_txn *txn, unsigned user_flags, MDBX_dbi *dbi, MD
    env->kvs[MAIN_DBI].clc.v.cmp = builtin_datacmp(main_flags);
    txn->dbs[MAIN_DBI].flags = main_flags;
    txn->dbs[MAIN_DBI].dupfix_size = 0;
-    int err = tbl_setup(env, &env->kvs[MAIN_DBI], &txn->dbs[MAIN_DBI]);
-    if (unlikely(err != MDBX_SUCCESS)) {
+    rc = tbl_setup(env, &env->kvs[MAIN_DBI], &txn->dbs[MAIN_DBI]);
+    if (unlikely(rc != MDBX_SUCCESS)) {
      txn->dbi_state[MAIN_DBI] = DBI_LINDO;
      txn->flags |= MDBX_TXN_ERROR;
      env->flags |= ENV_FATAL_ERROR;
-      return err;
+      return rc;
    }
    env->dbs_flags[MAIN_DBI] = main_flags | DB_VALID;
    txn->dbi_seqs[MAIN_DBI] = atomic_store32(&env->dbi_seqs[MAIN_DBI], seq, mo_AcquireRelease);
@@ -368,6 +386,7 @@ static int dbi_open_locked(MDBX_txn *txn, unsigned user_flags, MDBX_dbi *dbi, MD
  tASSERT(txn, env->kvs[MAIN_DBI].clc.k.cmp);

  /* Is the DB already open? */
+  defer_free_item_t *clone = nullptr;
  size_t slot = env->n_dbi;
  for (size_t scan = CORE_DBS; scan < env->n_dbi; ++scan) {
    if ((env->dbs_flags[scan] & DB_VALID) == 0) {
@@ -377,21 +396,49 @@ static int dbi_open_locked(MDBX_txn *txn, unsigned user_flags, MDBX_dbi *dbi, MD
    }
    if (env->kvs[MAIN_DBI].clc.k.cmp(&name, &env->kvs[scan].name) == 0) {
      slot = scan;
-      int err = dbi_check(txn, slot);
-      if (err == MDBX_BAD_DBI && txn->dbi_state[slot] == (DBI_OLDEN | DBI_LINDO)) {
+      rc = dbi_check(txn, slot);
+      if (rc == MDBX_BAD_DBI && txn->dbi_state[slot] == (DBI_OLDEN | DBI_LINDO)) {
        /* хендл использовался, стал невалидным,
-         * но теперь явно пере-открывается в этой транзакци */
+         * но теперь явно пере-открывается в этой транзакции */
        eASSERT(env, !txn->cursors[slot]);
        txn->dbi_state[slot] = DBI_LINDO;
-        err = dbi_check(txn, slot);
+        txn->dbi_seqs[slot] = 0;
+        rc = dbi_import(txn, slot);
+        /* TODO: FIXME */
      }
-      if (err == MDBX_SUCCESS) {
-        err = dbi_bind(txn, slot, user_flags, keycmp, datacmp);
-        if (likely(err == MDBX_SUCCESS)) {
-          goto done;
+      if (unlikely(rc != MDBX_SUCCESS))
+        return rc;
+
+      rc = dbi_bind(txn, slot, user_flags, keycmp, datacmp);
+      if (unlikely(rc != MDBX_SUCCESS))
+        return rc;
+
+      if (unlikely((txn->dbi_state[slot] & DBI_STALE) == 0))
+        goto done;
+
+      if (fastpath_slot /* уже был выполнен поиск посредством tbl_fetch() */) {
+        if (slot != fastpath_slot)
+          txn->dbs[slot] = txn->dbs[fastpath_slot];
+        if (user_flags & MDBX_CREATE) {
+          /* значит таблица уже была открытой, но проверка её наличия в fastpath вернула MDBX_NOTFOUND */
+          rc = MDBX_NOTFOUND;
+        } else {
+          /* значит в fastpath был найден пустой слот и проверка наличия таблицы завершилась успешно */
+          assert(rc == MDBX_SUCCESS);
        }
+      } else {
+        rc = tbl_fetch(txn, &maindb_cx->outer, slot, &name, user_flags);
      }
-      return err;
+
+      if (likely(rc == MDBX_SUCCESS))
+        goto done;
+
+      if (rc == MDBX_NOTFOUND && (user_flags & MDBX_CREATE)) {
+        name = env->kvs[scan].name;
+        goto create;
+      }
+
+      return dbi_gone(txn, slot, rc);
    }
  }

@@ -409,88 +456,72 @@ static int dbi_open_locked(MDBX_txn *txn, unsigned user_flags, MDBX_dbi *dbi, MD
    env->n_dbi = (unsigned)slot + 1;
  eASSERT(env, slot < env->n_dbi);

-  int err = dbi_check(txn, slot);
-  eASSERT(env, err == MDBX_BAD_DBI);
-  if (unlikely(err != MDBX_BAD_DBI))
+  rc = dbi_check(txn, slot);
+  eASSERT(env, rc == MDBX_BAD_DBI);
+  if (unlikely(rc != MDBX_BAD_DBI))
    return MDBX_PROBLEM;

  /* Find the DB info */
-  MDBX_val body;
-  cursor_couple_t cx;
-  int rc = cursor_init(&cx.outer, txn, MAIN_DBI);
-  if (unlikely(rc != MDBX_SUCCESS))
-    return rc;
-  rc = cursor_seek(&cx.outer, &name, &body, MDBX_SET).err;
+  rc = tbl_fetch(txn, &maindb_cx->outer, slot, &name, user_flags);
  if (unlikely(rc != MDBX_SUCCESS)) {
    if (rc != MDBX_NOTFOUND || !(user_flags & MDBX_CREATE))
      return rc;
-  } else {
-    /* make sure this is actually a table */
-    node_t *node = page_node(cx.outer.pg[cx.outer.top], cx.outer.ki[cx.outer.top]);
-    if (unlikely((node_flags(node) & (N_DUP | N_TREE)) != N_TREE))
-      return MDBX_INCOMPATIBLE;
-    if (!MDBX_DISABLE_VALIDATION && unlikely(body.iov_len != sizeof(tree_t))) {
-      ERROR("%s/%d: %s %zu", "MDBX_CORRUPTED", MDBX_CORRUPTED, "invalid table node size", body.iov_len);
-      return MDBX_CORRUPTED;
-    }
-    memcpy(&txn->dbs[slot], body.iov_base, sizeof(tree_t));
  }

  /* Done here so we cannot fail after creating a new DB */
-  defer_free_item_t *const clone = osal_malloc(dbi_namelen(name));
+  clone = osal_malloc(dbi_namelen(name));
  if (unlikely(!clone))
    return MDBX_ENOMEM;
  memcpy(clone, name.iov_base, name.iov_len);
  name.iov_base = clone;

+create:
+  tASSERT(txn, rc == MDBX_SUCCESS || rc == MDBX_NOTFOUND);
  uint8_t dbi_state = DBI_LINDO | DBI_VALID | DBI_FRESH;
  if (unlikely(rc != MDBX_SUCCESS)) {
-    /* MDBX_NOTFOUND and MDBX_CREATE: Create new DB */
-    tASSERT(txn, rc == MDBX_NOTFOUND);
-    body.iov_base = memset(&txn->dbs[slot], 0, body.iov_len = sizeof(tree_t));
-    txn->dbs[slot].root = P_INVALID;
-    txn->dbs[slot].mod_txnid = txn->txnid;
-    txn->dbs[slot].flags = user_flags & DB_PERSISTENT_FLAGS;
-    cx.outer.next = txn->cursors[MAIN_DBI];
-    txn->cursors[MAIN_DBI] = &cx.outer;
-    rc = cursor_put_checklen(&cx.outer, &name, &body, N_TREE | MDBX_NOOVERWRITE);
-    txn->cursors[MAIN_DBI] = cx.outer.next;
+    rc = tbl_create(txn, &maindb_cx->outer, slot, &name, user_flags);
    if (unlikely(rc != MDBX_SUCCESS))
      goto bailout;
-
    dbi_state |= DBI_DIRTY | DBI_CREAT;
-    txn->flags |= MDBX_TXN_DIRTY;
-    tASSERT(txn, (txn->dbi_state[MAIN_DBI] & DBI_DIRTY) != 0);
  }

  /* Got info, register DBI in this txn */
  const uint32_t seq = dbi_seq_next(env, slot);
-  eASSERT(env, env->dbs_flags[slot] == DB_POISON && !txn->cursors[slot] &&
-                   (txn->dbi_state[slot] & (DBI_LINDO | DBI_VALID)) == DBI_LINDO);
-  txn->dbi_state[slot] = dbi_state;
-  memcpy(&txn->dbs[slot], body.iov_base, sizeof(txn->dbs[slot]));
-  env->dbs_flags[slot] = txn->dbs[slot].flags;
-  rc = dbi_bind(txn, slot, user_flags, keycmp, datacmp);
-  if (unlikely(rc != MDBX_SUCCESS))
-    goto bailout;
+  eASSERT(env, !txn->cursors[slot]);
+  if (clone) {
+    eASSERT(env, env->dbs_flags[slot] == DB_POISON && (txn->dbi_state[slot] & (DBI_LINDO | DBI_VALID)) == DBI_LINDO);
+    txn->dbi_state[slot] = dbi_state;
+    env->dbs_flags[slot] = txn->dbs[slot].flags;
+    rc = dbi_bind(txn, slot, user_flags, keycmp, datacmp);
+    if (unlikely(rc != MDBX_SUCCESS))
+      goto bailout;

-  env->kvs[slot].name = name;
-  env->dbs_flags[slot] = txn->dbs[slot].flags | DB_VALID;
-  txn->dbi_seqs[slot] = atomic_store32(&env->dbi_seqs[slot], seq, mo_AcquireRelease);
+    env->kvs[slot].name = name;
+    env->dbs_flags[slot] = txn->dbs[slot].flags | DB_VALID;
+    txn->dbi_seqs[slot] = atomic_store32(&env->dbi_seqs[slot], seq, mo_AcquireRelease);
+  } else {
+    eASSERT(env, env->dbs_flags[slot] == (DB_VALID | (user_flags & DB_PERSISTENT_FLAGS)) &&
+                     env->dbs_flags[slot] == (DB_VALID | txn->dbs[slot].flags) &&
+                     txn->dbi_state[slot] == (DBI_LINDO | DBI_VALID | DBI_STALE));
+  }

 done:
-  *dbi = (MDBX_dbi)slot;
+  *(MDBX_dbi *)maindb_cx->userctx = (MDBX_dbi)slot;
  tASSERT(txn, slot < txn->n_dbi && (env->dbs_flags[slot] & DB_VALID) != 0);
  eASSERT(env, dbi_check(txn, slot) == MDBX_SUCCESS);
  return MDBX_SUCCESS;

 bailout:
-  eASSERT(env, !txn->cursors[slot] && !env->kvs[slot].name.iov_len && !env->kvs[slot].name.iov_base);
  txn->dbi_state[slot] &= DBI_LINDO | DBI_OLDEN;
  env->dbs_flags[slot] = 0;
-  osal_free(clone);
-  if (slot + 1 == env->n_dbi)
-    txn->n_dbi = env->n_dbi = (unsigned)slot;
+  if (clone) {
+    eASSERT(env, !txn->cursors[slot] && !env->kvs[slot].name.iov_len && !env->kvs[slot].name.iov_base);
+    osal_free(clone);
+    if (slot + 1 == env->n_dbi)
+      txn->n_dbi = env->n_dbi = (unsigned)slot;
+  } else {
+    eASSERT(env, name.iov_base == env->kvs[slot].name.iov_base);
+  }
  return rc;
 }

@@ -528,18 +559,20 @@ int dbi_open(MDBX_txn *txn, const MDBX_val *const name, unsigned user_flags, MDB
  if (unlikely(name->iov_len > txn->env->leaf_nodemax - NODESIZE - sizeof(tree_t)))
    return MDBX_EINVAL;

+  cursor_couple_t cx;
+  size_t fastpath_slot = 0;
 #if MDBX_ENABLE_DBI_LOCKFREE
  /* Is the DB already open? */
  const MDBX_env *const env = txn->env;
-  bool have_free_slot = env->n_dbi < env->max_dbi;
-  for (size_t i = CORE_DBS; i < env->n_dbi; ++i) {
-    if ((env->dbs_flags[i] & DB_VALID) == 0) {
-      have_free_slot = true;
+  size_t first_free_slot = env->n_dbi;
+  for (size_t slot = CORE_DBS; slot < env->n_dbi; ++slot) {
+    if ((env->dbs_flags[slot] & DB_VALID) == 0) {
+      first_free_slot = (first_free_slot < slot) ? first_free_slot : slot;
      continue;
    }

-    struct dbi_snap_result snap = dbi_snap(env, i);
-    const MDBX_val snap_name = env->kvs[i].name;
+    struct dbi_snap_result snap = dbi_snap(env, slot);
+    const MDBX_val snap_name = env->kvs[slot].name;
    const uint32_t main_seq = atomic_load32(&env->dbi_seqs[MAIN_DBI], mo_AcquireRelease);
    MDBX_cmp_func *const snap_cmp = env->kvs[MAIN_DBI].clc.k.cmp;
    if (unlikely(!(snap.flags & DB_VALID) || !snap_name.iov_base || !snap_name.iov_len || !snap_cmp))
@@ -547,10 +580,10 @@ int dbi_open(MDBX_txn *txn, const MDBX_val *const name, unsigned user_flags, MDB
      goto slowpath_locking;

    const bool name_match = snap_cmp(&snap_name, name) == 0;
-    if (unlikely(snap.sequence != atomic_load32(&env->dbi_seqs[i], mo_AcquireRelease) ||
+    if (unlikely(snap.sequence != atomic_load32(&env->dbi_seqs[slot], mo_AcquireRelease) ||
                 main_seq != atomic_load32(&env->dbi_seqs[MAIN_DBI], mo_AcquireRelease) ||
-                 snap.flags != env->dbs_flags[i] || snap_name.iov_base != env->kvs[i].name.iov_base ||
-                 snap_name.iov_len != env->kvs[i].name.iov_len))
+                 snap.flags != env->dbs_flags[slot] || snap_name.iov_base != env->kvs[slot].name.iov_base ||
+                 snap_name.iov_len != env->kvs[slot].name.iov_len))
      /* похоже на столкновение с параллельно работающим обновлением */
      goto slowpath_locking;

@@ -559,45 +592,65 @@ int dbi_open(MDBX_txn *txn, const MDBX_val *const name, unsigned user_flags, MDB

    osal_flush_incoherent_cpu_writeback();
    if (user_flags != MDBX_ACCEDE &&
-        (((user_flags ^ snap.flags) & DB_PERSISTENT_FLAGS) || (keycmp && keycmp != env->kvs[i].clc.k.cmp) ||
-         (datacmp && datacmp != env->kvs[i].clc.v.cmp)))
+        (((user_flags ^ snap.flags) & DB_PERSISTENT_FLAGS) || (keycmp && keycmp != env->kvs[slot].clc.k.cmp) ||
+         (datacmp && datacmp != env->kvs[slot].clc.v.cmp)))
      /* есть подозрение что пользователь открывает таблицу с другими флагами/атрибутами
       * или другими компараторами, поэтому уходим в безопасный режим */
      goto slowpath_locking;

-    rc = dbi_check(txn, i);
-    if (rc == MDBX_BAD_DBI && txn->dbi_state[i] == (DBI_OLDEN | DBI_LINDO)) {
+    rc = dbi_check(txn, slot);
+    if (rc == MDBX_BAD_DBI && txn->dbi_state[slot] == (DBI_OLDEN | DBI_LINDO)) {
      /* хендл использовался, стал невалидным,
-       * но теперь явно пере-открывается в этой транзакци */
-      eASSERT(env, !txn->cursors[i]);
-      txn->dbi_state[i] = DBI_LINDO;
-      rc = dbi_check(txn, i);
+       * но теперь явно пере-открывается в этой транзакции */
+      goto slowpath_locking;
    }
-    if (likely(rc == MDBX_SUCCESS)) {
-      if (unlikely(snap.sequence != atomic_load32(&env->dbi_seqs[i], mo_AcquireRelease) ||
-                   main_seq != atomic_load32(&env->dbi_seqs[MAIN_DBI], mo_AcquireRelease) ||
-                   snap.flags != env->dbs_flags[i] || snap_name.iov_base != env->kvs[i].name.iov_base ||
-                   snap_name.iov_len != env->kvs[i].name.iov_len))
-        /* похоже на столкновение с параллельно работающим обновлением */
-        goto slowpath_locking;
-      rc = dbi_bind(txn, i, user_flags, keycmp, datacmp);
-      if (likely(rc == MDBX_SUCCESS))
-        *dbi = (MDBX_dbi)i;
+    if (unlikely(rc != MDBX_SUCCESS))
+      return rc;
+
+    if (unlikely(snap.sequence != atomic_load32(&env->dbi_seqs[slot], mo_AcquireRelease) ||
+                 main_seq != atomic_load32(&env->dbi_seqs[MAIN_DBI], mo_AcquireRelease) ||
+                 snap.flags != env->dbs_flags[slot] || snap_name.iov_base != env->kvs[slot].name.iov_base ||
+                 snap_name.iov_len != env->kvs[slot].name.iov_len))
+      /* похоже на столкновение с параллельно работающим обновлением */
+      goto slowpath_locking;
+
+    rc = dbi_bind(txn, slot, user_flags, keycmp, datacmp);
+    if (unlikely(rc != MDBX_SUCCESS))
+      return rc;
+
+    tASSERT(txn, F_ISSET(txn->dbi_state[slot], DBI_LINDO | DBI_VALID));
+    if (txn->dbi_state[slot] & DBI_STALE) {
+      rc = tbl_fetch(txn, &cx.outer, fastpath_slot = slot, name, user_flags);
+      if (unlikely(rc != MDBX_SUCCESS)) {
+        if (rc == MDBX_NOTFOUND && (user_flags & MDBX_CREATE))
+          /* таблицы уже нет, но запрошено её пересоздание */
+          goto slowpath_locking;
+
+        return dbi_gone(txn, slot, rc);
+      }
+      txn->dbi_state[slot] -= DBI_STALE;
    }
-    return rc;
+    *dbi = (MDBX_dbi)slot;
+    return MDBX_SUCCESS;
  }

  /* Fail, if no free slot and max hit */
-  if (unlikely(!have_free_slot))
+  if (unlikely(first_free_slot >= env->max_dbi))
    return MDBX_DBS_FULL;

-slowpath_locking:
+  if (!(user_flags & MDBX_CREATE)) {
+    rc = tbl_fetch(txn, &cx.outer, fastpath_slot = first_free_slot, name, user_flags);
+    if (unlikely(rc != MDBX_SUCCESS))
+      return rc;
+  }

+slowpath_locking:
 #endif /* MDBX_ENABLE_DBI_LOCKFREE */

+  cx.userctx = dbi;
  rc = osal_fastmutex_acquire(&txn->env->dbi_lock);
  if (likely(rc == MDBX_SUCCESS)) {
-    rc = dbi_open_locked(txn, user_flags, dbi, keycmp, datacmp, *name);
+    rc = dbi_open_locked(txn, &cx, user_flags, keycmp, datacmp, *name, fastpath_slot);
    ENSURE(txn->env, osal_fastmutex_release(&txn->env->dbi_lock) == MDBX_SUCCESS);
  }
  return rc;
--- a/src/dbi.h
+++ b/src/dbi.h
@@ -11,7 +11,7 @@ MDBX_NOTHROW_CONST_FUNCTION MDBX_MAYBE_UNUSED MDBX_INTERNAL size_t dbi_bitmap_ct
                                                                                           intptr_t bmi);

 static inline size_t dbi_bitmap_ctz(const MDBX_txn *txn, intptr_t bmi) {
-  tASSERT(txn, bmi > 0);
+  tASSERT(txn, bmi != 0);
  STATIC_ASSERT(sizeof(bmi) >= sizeof(txn->dbi_sparse[0]));
 #if __GNUC_PREREQ(4, 1) || __has_builtin(__builtin_ctzl)
  if (sizeof(txn->dbi_sparse[0]) <= sizeof(int))
@@ -80,6 +80,7 @@ static inline bool dbi_foreach_step(const MDBX_txn *const txn, size_t *bitmap_it
 #define TXN_FOREACH_DBI_USER(TXN, I) TXN_FOREACH_DBI_FROM(TXN, I, CORE_DBS)

 MDBX_INTERNAL int dbi_import(MDBX_txn *txn, const size_t dbi);
+MDBX_INTERNAL int dbi_gone(MDBX_txn *txn, const size_t dbi, const int rc);

 struct dbi_snap_result {
  uint32_t sequence;
--- a/src/dxb.c
+++ b/src/dxb.c
@@ -532,7 +532,7 @@ __cold int dxb_setup(MDBX_env *env, const int lck_rc, const mdbx_mode_t mode_bit
    if (unlikely(err != MDBX_SUCCESS))
      return err;

-    err = osal_fallocate(env->lazy_fd, env->dxb_mmap.filesize = env->dxb_mmap.current = env->geo_in_bytes.now);
+    err = osal_fsetsize(env->lazy_fd, env->dxb_mmap.filesize = env->dxb_mmap.current = env->geo_in_bytes.now);
    if (unlikely(err != MDBX_SUCCESS))
      return err;

@@ -570,7 +570,7 @@ __cold int dxb_setup(MDBX_env *env, const int lck_rc, const mdbx_mode_t mode_bit

  size_t expected_filesize = 0;
  const size_t used_bytes = pgno2bytes(env, header.geometry.first_unallocated);
-  const size_t used_aligned2os_bytes = ceil_powerof2(used_bytes, globals.sys_pagesize);
+  const size_t used_aligned2os_bytes = ceil_powerof2(used_bytes, globals.sys_allocation_granularity);
  if ((env->flags & MDBX_RDONLY)    /* readonly */
      || lck_rc != MDBX_RESULT_TRUE /* not exclusive */
      || /* recovery mode */ env->stuck_meta >= 0) {
@@ -639,7 +639,7 @@ __cold int dxb_setup(MDBX_env *env, const int lck_rc, const mdbx_mode_t mode_bit
    env->geo_in_bytes.shrink = pgno_ceil2sp_bytes(env, pv2pages(header.geometry.shrink_pv));
  }

-  ENSURE(env, pgno_ceil2sp_bytes(env, header.geometry.now) == env->geo_in_bytes.now);
+  ENSURE(env, pgno_ceil2ag_bytes(env, header.geometry.now) == env->geo_in_bytes.now);
  ENSURE(env, env->geo_in_bytes.now >= used_bytes);
  if (!expected_filesize)
    expected_filesize = env->geo_in_bytes.now;
@@ -843,13 +843,13 @@ __cold int dxb_setup(MDBX_env *env, const int lck_rc, const mdbx_mode_t mode_bit
  if (lck_rc == /* lck exclusive */ MDBX_RESULT_TRUE) {
    //-------------------------------------------------- shrink DB & update geo
    /* re-check size after mmap */
-    if ((env->dxb_mmap.current & (globals.sys_pagesize - 1)) != 0 || env->dxb_mmap.current < used_bytes) {
+    if (floor_powerof2(env->dxb_mmap.current, globals.sys_pagesize) < used_bytes) {
      ERROR("unacceptable/unexpected datafile size %" PRIuPTR, env->dxb_mmap.current);
      return MDBX_PROBLEM;
    }
    if (env->dxb_mmap.current != env->geo_in_bytes.now) {
-      header.geometry.now = bytes2pgno(env, env->dxb_mmap.current);
-      NOTICE("need update meta-geo to filesize %" PRIuPTR " bytes, %" PRIaPGNO " pages", env->dxb_mmap.current,
+      header.geometry.now = bytes2pgno(env, env->geo_in_bytes.now);
+      NOTICE("need update meta-geo to filesize %" PRIuPTR " bytes, aligned %" PRIaPGNO " pages", env->geo_in_bytes.now,
             header.geometry.now);
    }

--- a/src/env.c
+++ b/src/env.c
@@ -305,6 +305,12 @@ __cold int env_open(MDBX_env *env, mdbx_mode_t mode) {

  env->fd4meta = env->lazy_fd;
 #if defined(_WIN32) || defined(_WIN64)
+  env->dxb_lock_event = CreateEventW(nullptr, true, false, nullptr);
+  if (unlikely(!env->dxb_lock_event))
+    return (int)GetLastError();
+  env->lck_lock_event = CreateEventW(nullptr, true, false, nullptr);
+  if (unlikely(!env->lck_lock_event))
+    return (int)GetLastError();
  eASSERT(env, env->ioring.overlapped_fd == 0);
  bool ior_direct = false;
  if (!(env->flags & (MDBX_RDONLY | MDBX_SAFE_NOSYNC | MDBX_NOMETASYNC | MDBX_EXCLUSIVE))) {
@@ -346,9 +352,6 @@ __cold int env_open(MDBX_env *env, mdbx_mode_t mode) {
                       &env->ioring.overlapped_fd, 0);
    if (unlikely(rc != MDBX_SUCCESS))
      return rc;
-    env->dxb_lock_event = CreateEventW(nullptr, true, false, nullptr);
-    if (unlikely(!env->dxb_lock_event))
-      return (int)GetLastError();
    osal_fseek(env->ioring.overlapped_fd, safe_parking_lot_offset);
  }
 #else
@@ -545,6 +548,10 @@ __cold int env_close(MDBX_env *env, bool resurrect_after_fork) {
    CloseHandle(env->dxb_lock_event);
    env->dxb_lock_event = INVALID_HANDLE_VALUE;
  }
+  if (env->lck_lock_event != INVALID_HANDLE_VALUE) {
+    CloseHandle(env->lck_lock_event);
+    env->lck_lock_event = INVALID_HANDLE_VALUE;
+  }
  eASSERT(env, !resurrect_after_fork);
  if (env->pathname_char) {
    osal_free(env->pathname_char);
--- a/src/essentials.h
+++ b/src/essentials.h
@@ -65,6 +65,9 @@ union logger_union {
 struct libmdbx_globals {
  bin128_t bootid;
  unsigned sys_pagesize, sys_allocation_granularity;
+#ifdef AT_UCACHEBSIZE
+  unsigned sys_unified_cache_block;
+#endif /* AT_UCACHEBSIZE */
  uint8_t sys_pagesize_ln2;
  uint8_t runtime_flags;
  uint8_t loglevel;
--- a/src/gc-get.c
+++ b/src/gc-get.c
@@ -878,7 +878,7 @@ pgr_t gc_alloc_ex(const MDBX_cursor *const mc, const size_t num, uint8_t flags)
  //---------------------------------------------------------------------------

  if (unlikely(!is_reclaimable(txn, mc, flags))) {
-    eASSERT(env, (txn->flags & txn_gc_drained) || num > 1);
+    eASSERT(env, (txn->flags & txn_gc_drained) || num > 1 || mc->tree == &txn->dbs[FREE_DBI]);
    goto no_gc;
  }

@@ -1090,7 +1090,7 @@ next_gc:
  rkl_t *rkl = &txn->wr.gc.reclaimed;
  const char *rkl_name = "reclaimed";
  if (mc->dbi_state != txn->dbi_state &&
-      (MDBX_DEBUG || pnl_size(txn->wr.repnl) > (size_t)gc->tree->height + gc->tree->height + 3)) {
+      (MDBX_DEBUG > 0 || pnl_size(txn->wr.repnl) > (size_t)gc->tree->height + gc->tree->height + 3)) {
    gc->next = txn->cursors[FREE_DBI];
    txn->cursors[FREE_DBI] = gc;
    ret.err = cursor_del(gc, 0);
--- a/src/gc-put.c
+++ b/src/gc-put.c
@@ -1290,9 +1290,12 @@ static int gc_fill_returned(MDBX_txn *txn, gcu_t *ctx) {
  rkl_iter_t iter = rkl_iterator(&txn->wr.gc.comeback, is_lifo(txn));
  size_t surplus = ctx->return_reserved_hi - amount, stored = 0;
  const uint64_t factor = ((uint64_t)surplus << 32) / ctx->return_reserved_hi;
-  TRACE("%s: amount %zu, slots %zu, surplus %zu (%zu..%zu), factor %.6f (%" PRIu64 " >> 32, sharp %.12f)",
-        dbg_prefix(ctx), amount, slots, surplus, ctx->return_reserved_lo, ctx->return_reserved_hi,
-        factor / (double)UINT32_MAX, factor, surplus / (double)ctx->return_reserved_hi);
+  ratio2digits_buffer_t factor_rough, factor_sharp;
+  TRACE("%s: amount %zu, slots %zu, surplus %zu (%zu..%zu), factor %s (%" PRIu64 " >> 32, sharp %s)", dbg_prefix(ctx),
+        amount, slots, surplus, ctx->return_reserved_lo, ctx->return_reserved_hi,
+        ratio2digits(factor, UINT32_MAX, &factor_rough, 6), factor,
+        ratio2digits(surplus, ctx->return_reserved_hi, &factor_sharp, 12));
+
  do {
    const size_t left = amount - stored;
    tASSERT(txn, left > 0 && left <= amount);
--- a/src/global.c
+++ b/src/global.c
@@ -27,8 +27,7 @@ BOOL APIENTRY DllMain(HANDLE module, DWORD reason, LPVOID reserved)
 #if !MDBX_MANUAL_MODULE_HANDLER
 static
 #endif /* !MDBX_MANUAL_MODULE_HANDLER */
-    void NTAPI
-    mdbx_module_handler(PVOID module, DWORD reason, PVOID reserved)
+    void NTAPI mdbx_module_handler(PVOID module, DWORD reason, PVOID reserved)
 #endif /* MDBX_BUILD_SHARED_LIBRARY */
 {
  (void)reserved;
@@ -176,8 +175,29 @@ __cold static __attribute__((__destructor__)) void mdbx_global_destructor(void)

 struct libmdbx_globals globals;

+static bool getenv_bool(const char *name, bool default_value) {
+  const char *value = osal_getenv(name, false);
+  if (value) {
+    if (*value == 0 /* implied ON */)
+      return true;
+    if (strcasecmp(value, "yes") == 0 || strcasecmp(value, "on") == 0 || strcasecmp(value, "true") == 0 ||
+        strcasecmp(value, "1") == 0)
+      return true;
+    if (strcasecmp(value, "no") == 0 || strcasecmp(value, "off") == 0 || strcasecmp(value, "false") == 0 ||
+        strcasecmp(value, "0") == 0)
+      return false;
+  }
+  return default_value;
+}
+
 __cold static void mdbx_init(void) {
-  globals.runtime_flags = ((MDBX_DEBUG) > 0) * MDBX_DBG_ASSERT + ((MDBX_DEBUG) > 1) * MDBX_DBG_AUDIT;
+  globals.runtime_flags = (getenv_bool("MDBX_DBG_ASSERT", (MDBX_DEBUG) > 0) ? MDBX_DBG_ASSERT : 0) |
+                          (getenv_bool("MDBX_DBG_AUDIT", (MDBX_DEBUG) > 1) ? MDBX_DBG_AUDIT : 0) |
+                          (getenv_bool("MDBX_DBG_JITTER", false) ? MDBX_DBG_JITTER : 0) |
+                          (getenv_bool("MDBX_DBG_DUMP", false) ? MDBX_DBG_DUMP : 0) |
+                          (getenv_bool("MDBX_DBG_LEGACY_MULTIOPEN", false) ? MDBX_DBG_LEGACY_MULTIOPEN : 0) |
+                          (getenv_bool("MDBX_DBG_LEGACY_OVERLAP", false) ? MDBX_DBG_LEGACY_OVERLAP : 0) |
+                          (getenv_bool("MDBX_DBG_DONT_UPGRADE", false) ? MDBX_DBG_DONT_UPGRADE : 0);
  globals.loglevel = MDBX_LOG_FATAL;
  ENSURE(nullptr, osal_fastmutex_init(&globals.debug_lock) == 0);
  osal_ctor();
@@ -379,6 +399,7 @@ __dll_export
 #else /* Windows */
    " MDBX_LOCKING=" MDBX_LOCKING_CONFIG
    " MDBX_USE_OFDLOCKS=" MDBX_USE_OFDLOCKS_CONFIG
+    " MDBX_USE_FALLOCATE=" MDBX_USE_FALLOCATE_CONFIG
 #endif /* !Windows */
    " MDBX_CACHELINE_SIZE=" MDBX_STRINGIFY(MDBX_CACHELINE_SIZE)
    " MDBX_CPU_WRITEBACK_INCOHERENT=" MDBX_STRINGIFY(MDBX_CPU_WRITEBACK_INCOHERENT)
--- a/src/internals.h
+++ b/src/internals.h
@@ -142,10 +142,10 @@ struct kvx {

 /* Non-shared DBI state flags inside transaction */
 enum dbi_state {
-  DBI_DIRTY = 0x01 /* DB was written in this txn */,
-  DBI_STALE = 0x02 /* Named-DB record is older than txnID */,
-  DBI_FRESH = 0x04 /* Named-DB handle opened in this txn */,
-  DBI_CREAT = 0x08 /* Named-DB handle created in this txn */,
+  DBI_DIRTY = 0x01 /* table was written in this txn */,
+  DBI_STALE = 0x02 /* cached table record is outdated and should be reloaded/refreshed */,
+  DBI_FRESH = 0x04 /* table handle opened in this txn */,
+  DBI_CREAT = 0x08 /* table handle created in this txn */,
  DBI_VALID = 0x10 /* Handle is valid, see also DB_VALID */,
  DBI_OLDEN = 0x40 /* Handle was closed/reopened outside txn */,
  DBI_LINDO = 0x80 /* Lazy initialization done for DBI-slot */,
@@ -352,6 +352,7 @@ struct MDBX_env {
  mdbx_filehandle_t dsync_fd, fd4meta;
 #if defined(_WIN32) || defined(_WIN64)
  HANDLE dxb_lock_event;
+  HANDLE lck_lock_event;
 #endif                  /* Windows */
  osal_mmap_t lck_mmap; /* The lock file */
  lck_t *lck;
@@ -481,7 +482,8 @@ struct MDBX_env {
 #if defined(_WIN32) || defined(_WIN64)
  osal_srwlock_t remap_guard;
  /* Workaround for LockFileEx and WriteFile multithread bug */
-  CRITICAL_SECTION windowsbug_lock;
+  CRITICAL_SECTION lck_event_cs;
+  CRITICAL_SECTION dxb_event_cs;
  char *pathname_char; /* cache of multi-byte representation of pathname
                             to the DB files */
 #else
--- a/src/lck-windows.c
+++ b/src/lck-windows.c
@@ -16,8 +16,11 @@
 #define LCK_WAITFOR 0
 #define LCK_DONTWAIT LOCKFILE_FAIL_IMMEDIATELY

-static int flock_with_event(HANDLE fd, HANDLE event, unsigned flags, size_t offset, size_t bytes) {
-  TRACE("lock>>: fd %p, event %p, flags 0x%x offset %zu, bytes %zu >>", fd, event, flags, offset, bytes);
+static int flock_ex(HANDLE fd, HANDLE event, unsigned flags, size_t offset, size_t bytes, unsigned timeout_ms) {
+  TRACE("lock>>: fd %p, timeout %u ms, event %p, flags 0x%x offset %zu, bytes %zu >>", fd, timeout_ms, event, flags,
+        offset, bytes);
+  assert(timeout_ms == 0 || (event && event != INVALID_HANDLE_VALUE));
+  assert(timeout_ms == 0 || (flags & LCK_DONTWAIT) == 0);
  OVERLAPPED ov;
  ov.Internal = 0;
  ov.InternalHigh = 0;
@@ -25,43 +28,43 @@ static int flock_with_event(HANDLE fd, HANDLE event, unsigned flags, size_t offs
  ov.Offset = (DWORD)offset;
  ov.OffsetHigh = HIGH_DWORD(offset);

-  int retry_left = (flags & LOCKFILE_FAIL_IMMEDIATELY) ? 3 : 0;
-  while (true) {
-    if (LockFileEx(fd, flags, 0, (DWORD)bytes, HIGH_DWORD(bytes), &ov)) {
-      TRACE("lock<<: fd %p, event %p, flags 0x%x offset %zu, bytes %zu << %s", fd, event, flags, offset, bytes, "done");
+  if (LockFileEx(fd, flags, 0, (DWORD)bytes, HIGH_DWORD(bytes), &ov)) {
+    TRACE("lock<<: fd %p, timeout %u ms, event %p, flags 0x%x offset %zu, bytes %zu << %s", fd, timeout_ms, event,
+          flags, offset, bytes, "done");
+    return MDBX_SUCCESS;
+  }
+
+  DWORD rc = GetLastError();
+  if (rc == ERROR_IO_PENDING) {
+    if (timeout_ms) {
+      rc = osal_waitstatus2errcode(WaitForSingleObject(event, timeout_ms));
+      if (rc != MDBX_SUCCESS) {
+        if (rc == ERROR_TIMEOUT)
+          rc = ERROR_LOCK_VIOLATION;
+        goto bailout;
+      }
+    }
+    if (GetOverlappedResult(fd, &ov, &rc, true)) {
+      TRACE("lock<<: fd %p, timeout %u ms, event %p, flags 0x%x offset %zu, bytes %zu << %s", fd, timeout_ms, event,
+            flags, offset, bytes, "overlapped-done");
      return MDBX_SUCCESS;
    }
-
-    DWORD rc = GetLastError();
-    if (rc == ERROR_IO_PENDING) {
-      if (event) {
-        if (GetOverlappedResult(fd, &ov, &rc, true)) {
-          TRACE("lock<<: fd %p, event %p, flags 0x%x offset %zu, bytes %zu << %s", fd, event, flags, offset, bytes,
-                "overlapped-done");
-          return MDBX_SUCCESS;
-        }
-        rc = GetLastError();
-      } else
-        CancelIo(fd);
-    }
-
-    if (rc != ERROR_LOCK_VIOLATION || --retry_left < 1) {
-      TRACE("lock<<: fd %p, event %p, flags 0x%x offset %zu, bytes %zu << err %d", fd, event, flags, offset, bytes,
-            (int)rc);
-      return (int)rc;
-    }
-
-    SleepEx(0, true);
+  bailout:
+    CancelIo(fd);
  }
+
+  TRACE("lock<<: fd %p, timeout %u ms, event %p, flags 0x%x offset %zu, bytes %zu << err %d", fd, timeout_ms, event,
+        flags, offset, bytes, (int)rc);
+  return (int)rc;
 }

-static inline int flock(HANDLE fd, unsigned flags, size_t offset, size_t bytes) {
-  return flock_with_event(fd, 0, flags, offset, bytes);
+static int flock_lck(const MDBX_env *env, unsigned flags, size_t offset, size_t bytes, unsigned timeout_ms) {
+  return flock_ex(env->lck_mmap.fd, env->lck_lock_event, flags, offset, bytes, timeout_ms);
 }

-static inline int flock_data(const MDBX_env *env, unsigned flags, size_t offset, size_t bytes) {
+static int flock_dxb(const MDBX_env *env, unsigned flags, size_t offset, size_t bytes) {
  const HANDLE fd4data = env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd;
-  return flock_with_event(fd4data, env->dxb_lock_event, flags, offset, bytes);
+  return flock_ex(fd4data, env->dxb_lock_event, flags, offset, bytes, 0);
 }

 static int funlock(mdbx_filehandle_t fd, size_t offset, size_t bytes) {
@@ -84,11 +87,11 @@ static int funlock(mdbx_filehandle_t fd, size_t offset, size_t bytes) {

 int lck_txn_lock(MDBX_env *env, bool dontwait) {
  if (dontwait) {
-    if (!TryEnterCriticalSection(&env->windowsbug_lock))
+    if (!TryEnterCriticalSection(&env->dxb_event_cs))
      return MDBX_BUSY;
  } else {
    __try {
-      EnterCriticalSection(&env->windowsbug_lock);
+      EnterCriticalSection(&env->dxb_event_cs);
    } __except ((GetExceptionCode() == 0xC0000194 /* STATUS_POSSIBLE_DEADLOCK / EXCEPTION_POSSIBLE_DEADLOCK */)
                    ? EXCEPTION_EXECUTE_HANDLER
                    : EXCEPTION_CONTINUE_SEARCH) {
@@ -100,34 +103,32 @@ int lck_txn_lock(MDBX_env *env, bool dontwait) {
  if (env->flags & MDBX_EXCLUSIVE)
    goto done;

-  const HANDLE fd4data = env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd;
-  int rc = flock_with_event(fd4data, env->dxb_lock_event,
-                            dontwait ? (LCK_EXCLUSIVE | LCK_DONTWAIT) : (LCK_EXCLUSIVE | LCK_WAITFOR), DXB_BODY);
+  int rc = flock_dxb(env, dontwait ? (LCK_EXCLUSIVE | LCK_DONTWAIT) : (LCK_EXCLUSIVE | LCK_WAITFOR), DXB_BODY);
+
  if (rc == MDBX_SUCCESS) {
  done:
    if (env->basal_txn)
      env->basal_txn->owner = osal_thread_self();
-    /* Zap: Failing to release lock 'env->windowsbug_lock'
+    /* Zap: Failing to release lock 'env->dxb_event_cs'
     *      in function 'mdbx_txn_lock' */
    MDBX_SUPPRESS_GOOFY_MSVC_ANALYZER(26115);
    return MDBX_SUCCESS;
  }

-  LeaveCriticalSection(&env->windowsbug_lock);
+  LeaveCriticalSection(&env->dxb_event_cs);
  return (!dontwait || rc != ERROR_LOCK_VIOLATION) ? rc : MDBX_BUSY;
 }

 void lck_txn_unlock(MDBX_env *env) {
  eASSERT(env, !env->basal_txn || env->basal_txn->owner == osal_thread_self());
  if ((env->flags & MDBX_EXCLUSIVE) == 0) {
-    const HANDLE fd4data = env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd;
-    int err = funlock(fd4data, DXB_BODY);
+    int err = funlock(env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd, DXB_BODY);
    if (err != MDBX_SUCCESS)
      mdbx_panic("%s failed: err %u", __func__, err);
  }
  if (env->basal_txn)
    env->basal_txn->owner = 0;
-  LeaveCriticalSection(&env->windowsbug_lock);
+  LeaveCriticalSection(&env->dxb_event_cs);
 }

 /*----------------------------------------------------------------------------*/
@@ -142,19 +143,34 @@ void lck_txn_unlock(MDBX_env *env) {
 #define LCK_UPPER LCK_UP_OFFSET, LCK_UP_LEN

 int lck_rdt_lock(MDBX_env *env) {
+  int rc;
  imports.srwl_AcquireShared(&env->remap_guard);
+
+  __try {
+    EnterCriticalSection(&env->lck_event_cs);
+  } __except ((GetExceptionCode() == 0xC0000194 /* STATUS_POSSIBLE_DEADLOCK / EXCEPTION_POSSIBLE_DEADLOCK */)
+                  ? EXCEPTION_EXECUTE_HANDLER
+                  : EXCEPTION_CONTINUE_SEARCH) {
+    rc = MDBX_EDEADLK;
+    goto bailout;
+  }
+
  if (env->lck_mmap.fd == INVALID_HANDLE_VALUE)
-    return MDBX_SUCCESS; /* readonly database in readonly filesystem */
+    goto done; /* readonly database in readonly filesystem */

  /* transition from S-? (used) to S-E (locked),
   * e.g. exclusive lock upper-part */
  if (env->flags & MDBX_EXCLUSIVE)
-    return MDBX_SUCCESS;
+    goto done;

-  int rc = flock(env->lck_mmap.fd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER);
-  if (rc == MDBX_SUCCESS)
+  rc = flock_lck(env, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER, 0);
+  if (rc == MDBX_SUCCESS) {
+  done:
+    MDBX_SUPPRESS_GOOFY_MSVC_ANALYZER(26115);
    return MDBX_SUCCESS;
+  }

+bailout:
  imports.srwl_ReleaseShared(&env->remap_guard);
  return rc;
 }
@@ -166,11 +182,12 @@ void lck_rdt_unlock(MDBX_env *env) {
    if (err != MDBX_SUCCESS)
      mdbx_panic("%s failed: err %u", __func__, err);
  }
+  LeaveCriticalSection(&env->lck_event_cs);
  imports.srwl_ReleaseShared(&env->remap_guard);
 }

 int osal_lockfile(mdbx_filehandle_t fd, bool wait) {
-  return flock(fd, wait ? LCK_EXCLUSIVE | LCK_WAITFOR : LCK_EXCLUSIVE | LCK_DONTWAIT, 0, DXB_MAXLEN);
+  return flock_ex(fd, 0, wait ? LCK_EXCLUSIVE | LCK_WAITFOR : LCK_EXCLUSIVE | LCK_DONTWAIT, 0, DXB_MAXLEN, 0);
 }

 static int suspend_and_append(mdbx_handle_array_t **array, const DWORD ThreadId) {
@@ -359,15 +376,18 @@ static void lck_unlock(MDBX_env *env) {
  }
 }

+#define TIMEOUT_SHORT_MS 121
+#define TIMEOUT_LONG_MS 900000 /* 15 min */
+
 /* Seize state as 'exclusive-write' (E-E and returns MDBX_RESULT_TRUE)
 * or as 'used' (S-? and returns MDBX_RESULT_FALSE).
 * Otherwise returns an error. */
-static int internal_seize_lck(HANDLE lfd) {
-  assert(lfd != INVALID_HANDLE_VALUE);
+static int internal_seize_lck(MDBX_env *env) {
+  assert(env->lck_mmap.fd != INVALID_HANDLE_VALUE);

  /* 1) now on ?-? (free), get ?-E (middle) */
  jitter4testing(false);
-  int rc = flock(lfd, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER);
+  int rc = flock_lck(env, LCK_EXCLUSIVE | LCK_WAITFOR, LCK_UPPER, TIMEOUT_LONG_MS);
  if (rc != MDBX_SUCCESS) {
    /* 2) something went wrong, give up */;
    ERROR("%s, err %u", "?-?(free) >> ?-E(middle)", rc);
@@ -376,7 +396,7 @@ static int internal_seize_lck(HANDLE lfd) {

  /* 3) now on ?-E (middle), try E-E (exclusive-write) */
  jitter4testing(false);
-  rc = flock(lfd, LCK_EXCLUSIVE | LCK_DONTWAIT, LCK_LOWER);
+  rc = flock_lck(env, LCK_EXCLUSIVE, LCK_LOWER, TIMEOUT_SHORT_MS);
  if (rc == MDBX_SUCCESS)
    return MDBX_RESULT_TRUE /* 4) got E-E (exclusive-write), done */;

@@ -384,7 +404,7 @@ static int internal_seize_lck(HANDLE lfd) {
  jitter4testing(false);
  if (rc != ERROR_SHARING_VIOLATION && rc != ERROR_LOCK_VIOLATION) {
    /* 6) something went wrong, give up */
-    rc = funlock(lfd, LCK_UPPER);
+    rc = funlock(env->lck_mmap.fd, LCK_UPPER);
    if (rc != MDBX_SUCCESS)
      mdbx_panic("%s(%s) failed: err %u", __func__, "?-E(middle) >> ?-?(free)", rc);
    return rc;
@@ -392,7 +412,7 @@ static int internal_seize_lck(HANDLE lfd) {

  /* 7) still on ?-E (middle), try S-E (locked) */
  jitter4testing(false);
-  rc = flock(lfd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER);
+  rc = flock_lck(env, LCK_SHARED, LCK_LOWER, TIMEOUT_LONG_MS);

  jitter4testing(false);
  if (rc != MDBX_SUCCESS)
@@ -400,7 +420,7 @@ static int internal_seize_lck(HANDLE lfd) {

  /* 8) now on S-E (locked) or still on ?-E (middle),
   *    transition to S-? (used) or ?-? (free) */
-  int err = funlock(lfd, LCK_UPPER);
+  int err = funlock(env->lck_mmap.fd, LCK_UPPER);
  if (err != MDBX_SUCCESS)
    mdbx_panic("%s(%s) failed: err %u", __func__, "X-E(locked/middle) >> X-?(used/free)", err);

@@ -409,8 +429,6 @@ static int internal_seize_lck(HANDLE lfd) {
 }

 int lck_seize(MDBX_env *env) {
-  const HANDLE fd4data = env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd;
-  assert(fd4data != INVALID_HANDLE_VALUE);
  if (env->flags & MDBX_EXCLUSIVE)
    return MDBX_RESULT_TRUE /* nope since files were must be opened
                               non-shareable */
@@ -419,13 +437,13 @@ int lck_seize(MDBX_env *env) {
  if (env->lck_mmap.fd == INVALID_HANDLE_VALUE) {
    /* LY: without-lck mode (e.g. on read-only filesystem) */
    jitter4testing(false);
-    int rc = flock_data(env, LCK_SHARED | LCK_DONTWAIT, DXB_WHOLE);
+    int rc = flock_dxb(env, LCK_SHARED | LCK_DONTWAIT, DXB_WHOLE);
    if (rc != MDBX_SUCCESS)
      ERROR("%s, err %u", "without-lck", rc);
    return rc;
  }

-  int rc = internal_seize_lck(env->lck_mmap.fd);
+  int rc = internal_seize_lck(env);
  jitter4testing(false);
  if (rc == MDBX_RESULT_TRUE && (env->flags & MDBX_RDONLY) == 0) {
    /* Check that another process don't operates in without-lck mode.
@@ -434,7 +452,7 @@ int lck_seize(MDBX_env *env) {
     *  - we need an exclusive lock for do so;
     *  - we can't lock meta-pages, otherwise other process could get an error
     *    while opening db in valid (non-conflict) mode. */
-    int err = flock_data(env, LCK_EXCLUSIVE | LCK_DONTWAIT, DXB_WHOLE);
+    int err = flock_dxb(env, LCK_EXCLUSIVE | LCK_DONTWAIT, DXB_WHOLE);
    if (err != MDBX_SUCCESS) {
      ERROR("%s, err %u", "lock-against-without-lck", err);
      jitter4testing(false);
@@ -442,7 +460,7 @@ int lck_seize(MDBX_env *env) {
      return err;
    }
    jitter4testing(false);
-    err = funlock(fd4data, DXB_WHOLE);
+    err = funlock(env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd, DXB_WHOLE);
    if (err != MDBX_SUCCESS)
      mdbx_panic("%s(%s) failed: err %u", __func__, "unlock-against-without-lck", err);
  }
@@ -451,9 +469,7 @@ int lck_seize(MDBX_env *env) {
 }

 int lck_downgrade(MDBX_env *env) {
-  const HANDLE fd4data = env->ioring.overlapped_fd ? env->ioring.overlapped_fd : env->lazy_fd;
  /* Transite from exclusive-write state (E-E) to used (S-?) */
-  assert(fd4data != INVALID_HANDLE_VALUE);
  assert(env->lck_mmap.fd != INVALID_HANDLE_VALUE);

  if (env->flags & MDBX_EXCLUSIVE)
@@ -465,7 +481,7 @@ int lck_downgrade(MDBX_env *env) {
    mdbx_panic("%s(%s) failed: err %u", __func__, "E-E(exclusive-write) >> ?-E(middle)", rc);

  /* 2) now at ?-E (middle), transition to S-E (locked) */
-  rc = flock(env->lck_mmap.fd, LCK_SHARED | LCK_DONTWAIT, LCK_LOWER);
+  rc = flock_lck(env, LCK_SHARED, LCK_LOWER, TIMEOUT_LONG_MS);
  if (rc != MDBX_SUCCESS) {
    /* 3) something went wrong, give up */;
    ERROR("%s, err %u", "?-E(middle) >> S-E(locked)", rc);
@@ -490,7 +506,7 @@ int lck_upgrade(MDBX_env *env, bool dont_wait) {

  /* 1) now on S-? (used), try S-E (locked) */
  jitter4testing(false);
-  int rc = flock(env->lck_mmap.fd, dont_wait ? LCK_EXCLUSIVE | LCK_DONTWAIT : LCK_EXCLUSIVE, LCK_UPPER);
+  int rc = flock_lck(env, dont_wait ? LCK_EXCLUSIVE | LCK_DONTWAIT : LCK_EXCLUSIVE, LCK_UPPER, 0);
  if (rc != MDBX_SUCCESS) {
    /* 2) something went wrong, give up */;
    VERBOSE("%s, err %u", "S-?(used) >> S-E(locked)", rc);
@@ -504,7 +520,7 @@ int lck_upgrade(MDBX_env *env, bool dont_wait) {

  /* 4) now on ?-E (middle), try E-E (exclusive-write) */
  jitter4testing(false);
-  rc = flock(env->lck_mmap.fd, dont_wait ? LCK_EXCLUSIVE | LCK_DONTWAIT : LCK_EXCLUSIVE, LCK_LOWER);
+  rc = flock_lck(env, dont_wait ? LCK_EXCLUSIVE | LCK_DONTWAIT : LCK_EXCLUSIVE, LCK_LOWER, 0);
  if (rc != MDBX_SUCCESS) {
    /* 5) something went wrong, give up */;
    VERBOSE("%s, err %u", "?-E(middle) >> E-E(exclusive-write)", rc);
@@ -547,7 +563,7 @@ int lck_destroy(MDBX_env *env, MDBX_env *inprocess_neighbor, const uint32_t curr
    if (synced && !inprocess_neighbor && env->lck_mmap.fd != INVALID_HANDLE_VALUE &&
        lck_upgrade(env, true) == MDBX_SUCCESS)
      /* this will fail if LCK is used/mmapped by other process(es) */
-      osal_ftruncate(env->lck_mmap.fd, 0);
+      osal_fsetsize(env->lck_mmap.fd, 0);
  }
  lck_unlock(env);
  return MDBX_SUCCESS;
--- a/src/logging_and_debug.h
+++ b/src/logging_and_debug.h
@@ -86,7 +86,10 @@ MDBX_INTERNAL void debug_log_va(int level, const char *function, int line, const
 #if MDBX_DEBUG
 #define ASSERT_FAIL(env, msg, func, line) mdbx_assert_fail(env, msg, func, line)
 #else /* MDBX_DEBUG */
-MDBX_NORETURN __cold void assert_fail(const char *msg, const char *func, unsigned line);
+#if !((defined(_WIN32) || defined(_WIN64)) && defined(_DEBUG) && !MDBX_WITHOUT_MSVC_CRT)
+MDBX_NORETURN
+#endif
+__cold void assert_fail(const char *msg, const char *func, unsigned line);
 #define ASSERT_FAIL(env, msg, func, line)                                                                              \
  do {                                                                                                                 \
    (void)(env);                                                                                                       \
--- a/src/options.h
+++ b/src/options.h
@@ -189,7 +189,7 @@

 /** Avoid dependence from MSVC CRT and use ntdll.dll instead. */
 #ifndef MDBX_WITHOUT_MSVC_CRT
-#if defined(MDBX_BUILD_CXX) && !MDBX_BUILD_CXX
+#if defined(MDBX_BUILD_CXX) && !MDBX_BUILD_CXX && (defined(_WIN32) || defined(_WIN64))
 #define MDBX_WITHOUT_MSVC_CRT 1
 #else
 #define MDBX_WITHOUT_MSVC_CRT 0
@@ -303,7 +303,8 @@
    ((defined(_POSIX_THREAD_ROBUST_PRIO_INHERIT) && _POSIX_THREAD_ROBUST_PRIO_INHERIT > 0) ||                          \
     (defined(_POSIX_THREAD_ROBUST_PRIO_PROTECT) && _POSIX_THREAD_ROBUST_PRIO_PROTECT > 0) ||                          \
     defined(PTHREAD_MUTEX_ROBUST) || defined(PTHREAD_MUTEX_ROBUST_NP)) &&                                             \
-    (!defined(__GLIBC__) || __GLIBC_PREREQ(2, 10) /* troubles with Robust mutexes before 2.10 */)
+    (!defined(__GLIBC__) || __GLIBC_PREREQ(2, 10) /* troubles with Robust mutexes before 2.10 */) &&                   \
+    !defined(__OHOS__) /* Harmony OS doesn't support robust mutexes at the end of 2025 */
 #define MDBX_LOCKING MDBX_LOCKING_POSIX2008
 #else
 #define MDBX_LOCKING MDBX_LOCKING_POSIX2001
@@ -358,6 +359,22 @@
 #error MDBX_USE_COPYFILERANGE must be defined as 0 or 1
 #endif /* MDBX_USE_COPYFILERANGE */

+/** Advanced: Using posix_fallocate() or fcntl(F_PREALLOCATE) on OSX (autodetection by default). */
+#ifndef MDBX_USE_FALLOCATE
+#if defined(__APPLE__)
+#define MDBX_USE_FALLOCATE 0 /* Too slow and unclean, but not required to prevent SIGBUS */
+#elif (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L) || (__GLIBC_PREREQ(2, 10) && defined(_GNU_SOURCE))
+#define MDBX_USE_FALLOCATE 1
+#else
+#define MDBX_USE_FALLOCATE 0
+#endif
+#define MDBX_USE_FALLOCATE_CONFIG "AUTO=" MDBX_STRINGIFY(MDBX_USE_FALLOCATE)
+#elif !(MDBX_USE_FALLOCATE == 0 || MDBX_USE_FALLOCATE == 1)
+#error MDBX_USE_FALLOCATE must be defined as 0 or 1
+#else
+#define MDBX_USE_FALLOCATE_CONFIG MDBX_STRINGIFY(MDBX_USE_FALLOCATE)
+#endif /* MDBX_USE_FALLOCATE */
+
 //------------------------------------------------------------------------------

 #ifndef MDBX_CPU_WRITEBACK_INCOHERENT
--- a/src/osal.c
+++ b/src/osal.c
@@ -14,23 +14,6 @@
 #include <crtdbg.h>
 #endif

-static int waitstatus2errcode(DWORD result) {
-  switch (result) {
-  case WAIT_OBJECT_0:
-    return MDBX_SUCCESS;
-  case WAIT_FAILED:
-    return (int)GetLastError();
-  case WAIT_ABANDONED:
-    return ERROR_ABANDONED_WAIT_0;
-  case WAIT_IO_COMPLETION:
-    return ERROR_USER_APC;
-  case WAIT_TIMEOUT:
-    return ERROR_TIMEOUT;
-  default:
-    return ERROR_UNHANDLED_ERROR;
-  }
-}
-
 /* Map a result from an NTAPI call to WIN32 error code. */
 static int ntstatus2errcode(NTSTATUS status) {
  DWORD dummy;
@@ -205,7 +188,7 @@ __cold void mdbx_assert_fail(const MDBX_env *env, const char *msg, const char *f
  assert_fail(msg, func, line);
 }

-MDBX_NORETURN __cold void assert_fail(const char *msg, const char *func, unsigned line) {
+__cold void assert_fail(const char *msg, const char *func, unsigned line) {
 #endif /* MDBX_DEBUG */

  if (globals.logger.ptr)
@@ -224,13 +207,19 @@ MDBX_NORETURN __cold void assert_fail(const char *msg, const char *func, unsigne

  while (1) {
 #if defined(_WIN32) || defined(_WIN64)
-#if !MDBX_WITHOUT_MSVC_CRT && defined(_DEBUG)
-    _CrtDbgReport(_CRT_ASSERT, func ? func : "unknown", line, "libmdbx", "assertion failed: %s", msg);
+#if defined(_DEBUG) && !MDBX_WITHOUT_MSVC_CRT
+    if (_CrtDbgReport(_CRT_ASSERT, func ? func : "unknown", line, "libmdbx", "assertion failed: %s", msg) == 0)
+      return /* user chooses the "Continue" button */;
+    else {
+      /* user chooses the "Retry" button */
+      if (IsDebuggerPresent())
+        DebugBreak();
+    }
 #else
    if (IsDebuggerPresent())
      DebugBreak();
-#endif
    FatalExit(STATUS_ASSERTION_FAILURE);
+#endif
 #else
    abort();
 #endif
@@ -252,14 +241,14 @@ __cold void mdbx_panic(const char *fmt, ...) {

  while (1) {
 #if defined(_WIN32) || defined(_WIN64)
-#if !MDBX_WITHOUT_MSVC_CRT && defined(_DEBUG)
+#if defined(_DEBUG) && !MDBX_WITHOUT_MSVC_CRT
    _CrtDbgReport(_CRT_ASSERT, "mdbx.c", 0, "libmdbx", "panic: %s", const_message);
 #else
    OutputDebugStringA("\r\nMDBX-PANIC: ");
    OutputDebugStringA(const_message);
+#endif
    if (IsDebuggerPresent())
      DebugBreak();
-#endif
    FatalExit(ERROR_UNHANDLED_ERROR);
 #else
    __assert_fail(const_message, "mdbx-panic", 0, const_message);
@@ -414,7 +403,7 @@ int osal_condpair_destroy(osal_condpair_t *condpair) {
 int osal_condpair_lock(osal_condpair_t *condpair) {
 #if defined(_WIN32) || defined(_WIN64)
  DWORD code = WaitForSingleObject(condpair->mutex, INFINITE);
-  return waitstatus2errcode(code);
+  return osal_waitstatus2errcode(code);
 #else
  return osal_pthread_mutex_lock(&condpair->mutex);
 #endif
@@ -444,7 +433,7 @@ int osal_condpair_wait(osal_condpair_t *condpair, bool part) {
    if (code == WAIT_OBJECT_0)
      return MDBX_SUCCESS;
  }
-  return waitstatus2errcode(code);
+  return osal_waitstatus2errcode(code);
 #else
  return pthread_cond_wait(&condpair->cond[part], &condpair->mutex);
 #endif
@@ -1186,7 +1175,7 @@ int osal_openfile(const enum osal_openfile_purpose purpose, const MDBX_env *env,
  case MDBX_OPEN_LCK:
    CreationDisposition = OPEN_ALWAYS;
    DesiredAccess |= GENERIC_READ | GENERIC_WRITE;
-    FlagsAndAttributes |= FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_TEMPORARY;
+    FlagsAndAttributes |= FILE_ATTRIBUTE_HIDDEN | FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_OVERLAPPED;
    break;
  case MDBX_OPEN_DXB_READ:
    CreationDisposition = OPEN_EXISTING;
@@ -1594,8 +1583,7 @@ int osal_is_pipe(mdbx_filehandle_t fd) {
 #endif
 }

-/* truncate file: just set the length of a file */
-int osal_ftruncate(mdbx_filehandle_t fd, uint64_t length) {
+int osal_fsetsize(mdbx_filehandle_t fd, const uint64_t length) {
 #if defined(_WIN32) || defined(_WIN64)
  if (imports.SetFileInformationByHandle) {
    FILE_END_OF_FILE_INFO EndOfFileInfo;
@@ -1610,31 +1598,58 @@ int osal_ftruncate(mdbx_filehandle_t fd, uint64_t length) {
  }
 #else
  STATIC_ASSERT_MSG(sizeof(off_t) >= sizeof(size_t), "libmdbx requires 64-bit file I/O on 64-bit systems");
-  return ftruncate(fd, length) == 0 ? MDBX_SUCCESS : errno;
-#endif
-}

-/* extend file: set the length of a file AND ensure the space has been allocated */
-int osal_fallocate(mdbx_filehandle_t fd, uint64_t length) {
-  assert(length > 0);
-  int err = MDBX_RESULT_TRUE;
-#if (defined(__linux__) || defined(__gnu_linux__)) &&                                                                  \
-    ((defined(_GNU_SOURCE) && __GLIBC_PREREQ(2, 10)) || (defined(__ANDROID_API__) && __ANDROID_API__ >= 21))
-  err = fallocate(fd, 0, 0, length) ? ignore_enosys_and_eremote(errno) : MDBX_SUCCESS;
-#elif defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L && !defined(__APPLE__)
-  err = posix_fallocate(fd, 0, length) ? ignore_enosys_and_eremote(errno) : MDBX_SUCCESS;
-#elif defined(__APPLE__)
-  fstore_t store = {F_ALLOCATEALL, F_PEOFPOSMODE, 0, length, 0};
-  if (fcntl(fd, F_PREALLOCATE, &store))
-    err = ignore_enosys_and_eremote(errno);
-#endif /* Apple */
-#if !defined(_WIN32) && !defined(_WIN64)
-  /* Workaround for testing: ignore ENOSPC for TMPFS/RAMFS.
-   * This is insignificant for production, but it helps in some tests using /dev/shm inside docker/containers. */
-  if (err == ENOSPC && osal_check_fs_incore(fd) == MDBX_RESULT_TRUE)
-    err = MDBX_RESULT_TRUE;
+#if MDBX_USE_FALLOCATE
+  struct stat info;
+  if (unlikely(fstat(fd, &info)))
+    return errno;
+
+  const uint64_t allocated = UINT64_C(512) * info.st_blocks;
+  if (length > allocated) {
+#if defined(__APPLE__)
+    fstore_t store = {
+        .fst_flags = F_ALLOCATECONTIG, .fst_posmode = F_PEOFPOSMODE, .fst_offset = 0, .fst_length = length};
+    int err = MDBX_SUCCESS;
+    if (fcntl(fd, F_PREALLOCATE, &store)) {
+      /* TODO: implement step-by-step allocation in chunks of 16384, 8192, 4094, 2048, 1024 Kb */
+      store.fst_flags = F_ALLOCATEALL;
+      if (fcntl(fd, F_PREALLOCATE, &store))
+        err = errno;
+    }
+#elif defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200112L
+    const int err = posix_fallocate(fd, 0, length);
+    if (!err && length > (uint64_t)info.st_size)
+      info.st_size = length /* posix_fallocate() extends the file */;
+#else
+    const int err = fallocate(fd, 0, 0, length) ? errno : MDBX_SUCCESS;
+    if (!err && length > (uint64_t)info.st_size)
+      info.st_size = length /* fallocate() extends the file */;
+#endif
+    if (unlikely(err) && ignore_enosys_and_eremote(err) != MDBX_RESULT_TRUE) {
+      /* Workaround for testing: ignore ENOSPC for TMPFS/RAMFS.
+       * This is insignificant for production, but it helps in some tests using /dev/shm inside docker/containers. */
+      if (err != ENOSPC || osal_check_fs_incore(fd) != MDBX_RESULT_TRUE)
+        return err;
+    }
+  }
+
+  if (length == (uint64_t)info.st_size)
+    return MDBX_SUCCESS;
+#endif
+
+#if defined(__linux__) || defined(__gnu_linux__)
+  if (globals.linux_kernel_version < 0x05110000 && globals.linux_kernel_version >= 0x050a0000) {
+    struct statfs statfs_info;
+    if (fstatfs(fd, &statfs_info))
+      return errno;
+    if (statfs_info.f_type == 0xEF53 /* EXT4_SUPER_MAGIC */ && unlikely(fdatasync(fd)))
+      return errno;
+  }
+#endif /* Linux */
+
+  return unlikely(ftruncate(fd, length)) ? errno : MDBX_SUCCESS;
+
 #endif /* !Windows */
-  return (err == MDBX_RESULT_TRUE) ? osal_ftruncate(fd, length) : err;
 }

 int osal_fseek(mdbx_filehandle_t fd, uint64_t pos) {
@@ -1662,7 +1677,7 @@ int osal_thread_create(osal_thread_t *thread, THREAD_RESULT(THREAD_CALL *start_r
 int osal_thread_join(osal_thread_t thread) {
 #if defined(_WIN32) || defined(_WIN64)
  DWORD code = WaitForSingleObject(thread, INFINITE);
-  return waitstatus2errcode(code);
+  return osal_waitstatus2errcode(code);
 #else
  void *unused_retval = &unused_retval;
  return pthread_join(thread, &unused_retval);
@@ -2087,8 +2102,8 @@ int osal_mmap(const int flags, osal_mmap_t *map, size_t size, const size_t limit
    return err;

  if ((flags & MDBX_RDONLY) == 0 && (options & MMAP_OPTION_SETLENGTH) != 0) {
-    err = osal_fallocate(map->fd, size);
-    VERBOSE("ftruncate %zu, err %d", size, err);
+    err = osal_fsetsize(map->fd, size);
+    VERBOSE("osal_fsetsize %zu, err %d", size, err);
    if (err != MDBX_SUCCESS)
      return err;
    map->filesize = size;
@@ -2333,7 +2348,7 @@ retry_file_and_section:
  }

  if ((flags & MDBX_RDONLY) == 0 && map->filesize != size) {
-    err = osal_fallocate(map->fd, size);
+    err = osal_fsetsize(map->fd, size);
    if (err == MDBX_SUCCESS)
      map->filesize = size;
    /* ignore error, because Windows unable shrink file
@@ -2413,11 +2428,11 @@ retry_mapview:;
  } else {
    if (map->filesize != size) {
      if (size > map->filesize) {
-        rc = osal_fallocate(map->fd, size);
-        VERBOSE("f%s-%s %zu, err %d", "allocate", "extend", size, rc);
+        rc = osal_fsetsize(map->fd, size);
+        VERBOSE("osal_fsetsize-%s %zu, err %d", "extend", size, rc);
      } else if (flags & txn_shrink_allowed) {
-        rc = osal_ftruncate(map->fd, size);
-        VERBOSE("f%s-%s %zu, err %d", "truncate", "shrink", size, rc);
+        rc = osal_fsetsize(map->fd, size);
+        VERBOSE("osal_fsetsize-%s %zu, err %d", "shrink", size, rc);
      }
      if (unlikely(rc != MDBX_SUCCESS))
        return rc;
@@ -3458,6 +3473,35 @@ bin128_t osal_guid(const MDBX_env *env) {
  return uuid;
 }

+const char *osal_getenv(const char *name, bool secure) {
+  (void)secure;
+#if defined(_WIN32) || defined(_WIN64)
+  static char buf[42];
+  SetLastError(ERROR_OUT_OF_PAPER);
+  const size_t len = GetEnvironmentVariableA(name, buf, sizeof(buf));
+  if (len >= sizeof(buf))
+    /* no idea haw to handle */
+    return nullptr;
+  if (len != 0)
+    return buf;
+  switch (GetLastError()) {
+  case ERROR_OUT_OF_PAPER:
+    return "";
+  default:
+    /* no idea to do in case of other error */
+  case ERROR_ENVVAR_NOT_FOUND:
+    return nullptr;
+  }
+  return (GetLastError() == ERROR_ENVVAR_NOT_FOUND) ? nullptr : "";
+#else
+#if defined(_GNU_SOURCE) && __GLIBC_PREREQ(2, 17)
+  if (secure)
+    return secure_getenv(name);
+#endif /* glibc >= 2.17 */
+  return getenv(name);
+#endif
+}
+
 /*--------------------------------------------------------------------------*/

 void osal_ctor(void) {
@@ -3472,14 +3516,26 @@ void osal_ctor(void) {
  SYSTEM_INFO si;
  GetSystemInfo(&si);
  globals.sys_pagesize = si.dwPageSize;
-  globals.sys_allocation_granularity = si.dwAllocationGranularity;
+  globals.sys_allocation_granularity =
+      (si.dwAllocationGranularity > globals.sys_pagesize) ? si.dwAllocationGranularity : globals.sys_pagesize;
 #else
  globals.sys_pagesize = sysconf(_SC_PAGE_SIZE);
  globals.sys_allocation_granularity = (MDBX_WORDBITS > 32) ? 65536 : 16384;
  globals.sys_allocation_granularity = (globals.sys_allocation_granularity >= globals.sys_pagesize * 2)
                                           ? globals.sys_allocation_granularity
                                           : globals.sys_pagesize * 4;
+#ifdef AT_UCACHEBSIZE
+  const size_t unified_cache_block_size = getauxval(AT_UCACHEBSIZE);
+  globals.sys_unified_cache_block = globals.sys_pagesize;
+  if (unified_cache_block_size > 0 && unified_cache_block_size < INT_MAX) {
+    globals.sys_unified_cache_block = (unsigned)unified_cache_block_size;
+    if (globals.sys_unified_cache_block > globals.sys_pagesize)
+      globals.sys_allocation_granularity = globals.sys_unified_cache_block;
+  }
+#endif /* AT_UCACHEBSIZE */
 #endif
+  if (globals.sys_allocation_granularity > 4 * MEGABYTE && globals.sys_pagesize < MEGABYTE)
+    globals.sys_allocation_granularity = 4 * MEGABYTE;
  assert(globals.sys_pagesize > 0 && (globals.sys_pagesize & (globals.sys_pagesize - 1)) == 0);
  assert(globals.sys_allocation_granularity >= globals.sys_pagesize &&
         globals.sys_allocation_granularity % globals.sys_pagesize == 0);
--- a/src/osal.h
+++ b/src/osal.h
@@ -133,6 +133,14 @@ static inline void osal_free(void *ptr) { HeapFree(GetProcessHeap(), 0, ptr); }
 #define vsnprintf _vsnprintf /* ntdll */
 #endif

+#ifndef strcasecmp
+#define strcasecmp _stricmp /* ntdll */
+#endif
+
+#ifndef strncasecmp
+#define strncasecmp _strnicmp /* ntdll */
+#endif
+
 #else /*----------------------------------------------------------------------*/

 typedef pthread_t osal_thread_t;
@@ -171,7 +179,7 @@ typedef char pathchar_t;
 #define MDBX_PRIsPATH "s"
 #endif

-static inline bool osal_yield(void) {
+MDBX_MAYBE_UNUSED static inline bool osal_yield(void) {
 #if defined(_WIN32) || defined(_WIN64)
  return SleepEx(0, true) == WAIT_IO_COMPLETION;
 #else
@@ -198,6 +206,23 @@ typedef struct osal_mmap {

 #define MDBX_HAVE_PWRITEV 0

+static inline int osal_waitstatus2errcode(DWORD result) {
+  switch (result) {
+  case WAIT_OBJECT_0:
+    return MDBX_SUCCESS;
+  case WAIT_FAILED:
+    return (int)GetLastError();
+  case WAIT_ABANDONED:
+    return ERROR_ABANDONED_WAIT_0;
+  case WAIT_IO_COMPLETION:
+    return ERROR_USER_APC;
+  case WAIT_TIMEOUT:
+    return ERROR_TIMEOUT;
+  default:
+    return ERROR_UNHANDLED_ERROR;
+  }
+}
+
 #elif defined(__ANDROID_API__)

 #if __ANDROID_API__ < 24
@@ -441,8 +466,7 @@ enum osal_syncmode_bits {
 };

 MDBX_INTERNAL int osal_fsync(mdbx_filehandle_t fd, const enum osal_syncmode_bits mode_bits);
-MDBX_INTERNAL int osal_ftruncate(mdbx_filehandle_t fd, uint64_t length);
-MDBX_INTERNAL int osal_fallocate(mdbx_filehandle_t fd, uint64_t length);
+MDBX_INTERNAL int osal_fsetsize(mdbx_filehandle_t fd, const uint64_t length);
 MDBX_INTERNAL int osal_fseek(mdbx_filehandle_t fd, uint64_t pos);
 MDBX_INTERNAL int osal_filesize(mdbx_filehandle_t fd, uint64_t *length);

@@ -468,6 +492,7 @@ MDBX_MAYBE_UNUSED static inline bool osal_isdirsep(pathchar_t c) {
      c == '/';
 }

+MDBX_INTERNAL const char *osal_getenv(const char *name, bool secure);
 MDBX_INTERNAL bool osal_pathequal(const pathchar_t *l, const pathchar_t *r, size_t len);
 MDBX_INTERNAL pathchar_t *osal_fileext(const pathchar_t *pathname, size_t len);
 MDBX_INTERNAL int osal_fileexists(const pathchar_t *pathname);
--- a/src/preface.h
+++ b/src/preface.h
@@ -43,7 +43,7 @@
 #if defined(_WIN32) || defined(_WIN64) || defined(_WINDOWS)

 #ifndef _WIN32_WINNT
-#define _WIN32_WINNT 0x0601 /* Windows 7 */
+#define _WIN32_WINNT 0x0A00 /* Windows 10 */
 #endif                      /* _WIN32_WINNT */

 #if !defined(_CRT_SECURE_NO_WARNINGS)
@@ -428,6 +428,10 @@ __extern_C key_t ftok(const char *, int);
 #include <sys/time.h>
 #include <sys/uio.h>

+#if __GLIBC_PREREQ(2, 16) || __has_include(<sys/auxv.h>)
+#include <sys/auxv.h>
+#endif /* glibc >= 2.16 */
+
 #endif /*---------------------------------------------------------------------*/

 #if defined(__ANDROID_API__) || defined(ANDROID)
--- a/src/proto.h
+++ b/src/proto.h
@@ -88,7 +88,7 @@ MDBX_INTERNAL int txn_ro_end(MDBX_txn *txn, unsigned mode);

 /* env.c */
 MDBX_INTERNAL int env_open(MDBX_env *env, mdbx_mode_t mode);
-MDBX_INTERNAL int env_info(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo *out, size_t bytes, troika_t *troika);
+MDBX_INTERNAL int env_info(const MDBX_env *env, const MDBX_txn *txn, MDBX_envinfo *out, troika_t *troika);
 MDBX_INTERNAL int env_sync(MDBX_env *env, bool force, bool nonblock);
 MDBX_INTERNAL int env_close(MDBX_env *env, bool resurrect_after_fork);
 MDBX_INTERNAL MDBX_txn *env_owned_wrtxn(const MDBX_env *env);
@@ -109,8 +109,12 @@ MDBX_INTERNAL void recalculate_merge_thresholds(MDBX_env *env);
 MDBX_INTERNAL void recalculate_subpage_thresholds(MDBX_env *env);

 /* table.c */
-MDBX_INTERNAL int __must_check_result tbl_fetch(MDBX_txn *txn, size_t dbi);
+MDBX_INTERNAL int __must_check_result tbl_fetch(MDBX_txn *txn, MDBX_cursor *mc, size_t dbi, const MDBX_val *name,
+                                                unsigned wanna_flags);
+MDBX_INTERNAL int __must_check_result tbl_create(MDBX_txn *txn, MDBX_cursor *mc, size_t slot, const MDBX_val *name,
+                                                 unsigned db_flags);
 MDBX_INTERNAL int __must_check_result tbl_setup(const MDBX_env *env, volatile kvx_t *const kvx, const tree_t *const db);
+MDBX_INTERNAL int __must_check_result tbl_refresh(MDBX_txn *txn, size_t dbi);

 /* coherency.c */
 MDBX_INTERNAL bool coherency_check_meta(const MDBX_env *env, const volatile meta_t *meta, bool report);
--- a/src/table.c
+++ b/src/table.c
@@ -37,67 +37,99 @@ int tbl_setup(const MDBX_env *env, volatile kvx_t *const kvx, const tree_t *cons
  return MDBX_SUCCESS;
 }

-int tbl_fetch(MDBX_txn *txn, size_t dbi) {
-  cursor_couple_t couple;
-  int rc = cursor_init(&couple.outer, txn, MAIN_DBI);
-  if (unlikely(rc != MDBX_SUCCESS))
-    return rc;
+int tbl_fetch(MDBX_txn *txn, MDBX_cursor *mc, size_t dbi, const MDBX_val *name, unsigned wanna_flags) {
+  int err = cursor_init(mc, txn, MAIN_DBI);
+  if (unlikely(err != MDBX_SUCCESS))
+    return err;

-  kvx_t *const kvx = &txn->env->kvs[dbi];
-  rc = tree_search(&couple.outer, &kvx->name, 0);
-  if (unlikely(rc != MDBX_SUCCESS)) {
-  bailout:
-    NOTICE("dbi %zu refs to inaccessible table `%.*s` for txn %" PRIaTXN " (err %d)", dbi, (int)kvx->name.iov_len,
-           (const char *)kvx->name.iov_base, txn->txnid, rc);
-    return (rc == MDBX_NOTFOUND) ? MDBX_BAD_DBI : rc;
+  err = tree_search(mc, name, 0);
+  if (unlikely(err != MDBX_SUCCESS)) {
+    if (err == MDBX_NOTFOUND)
+      goto notfound;
+    return err;
+  }
+
+  struct node_search_result nsr = node_search(mc, name);
+  if (unlikely(!nsr.exact)) {
+  notfound:
+    if (dbi < txn->env->n_dbi && (txn->env->dbs_flags[dbi] & DB_VALID) && !(wanna_flags & MDBX_CREATE))
+      NOTICE("dbi %zu refs to non-existing table `%.*s` for txn %" PRIaTXN " (err %d)", dbi, (int)name->iov_len,
+             (const char *)name->iov_base, txn->txnid, err);
+    return MDBX_NOTFOUND;
+  }
+
+  if (unlikely((node_flags(nsr.node) & (N_DUP | N_TREE)) != N_TREE)) {
+    NOTICE("dbi %zu refs to not a named table `%.*s` for txn %" PRIaTXN " (%s)", dbi, (int)name->iov_len,
+           (const char *)name->iov_base, txn->txnid, "wrong node-flags");
+    return MDBX_INCOMPATIBLE /* not a named DB */;
  }

  MDBX_val data;
-  struct node_search_result nsr = node_search(&couple.outer, &kvx->name);
-  if (unlikely(!nsr.exact)) {
-    rc = MDBX_NOTFOUND;
-    goto bailout;
-  }
-  if (unlikely((node_flags(nsr.node) & (N_DUP | N_TREE)) != N_TREE)) {
-    NOTICE("dbi %zu refs to not a named table `%.*s` for txn %" PRIaTXN " (%s)", dbi, (int)kvx->name.iov_len,
-           (const char *)kvx->name.iov_base, txn->txnid, "wrong flags");
-    return MDBX_INCOMPATIBLE; /* not a named DB */
+  err = node_read(mc, nsr.node, &data, mc->pg[mc->top]);
+  if (unlikely(err != MDBX_SUCCESS))
+    return err;
+
+  if (unlikely(data.iov_len < sizeof(tree_t))) {
+    NOTICE("dbi %zu refs to not a named table `%.*s` for txn %" PRIaTXN " (%s)", dbi, (int)name->iov_len,
+           (const char *)name->iov_base, txn->txnid, "wrong record-size");
+    return MDBX_INCOMPATIBLE /* not a named DB */;
  }

-  rc = node_read(&couple.outer, nsr.node, &data, couple.outer.pg[couple.outer.top]);
-  if (unlikely(rc != MDBX_SUCCESS))
-    return rc;
-
-  if (unlikely(data.iov_len != sizeof(tree_t))) {
-    NOTICE("dbi %zu refs to not a named table `%.*s` for txn %" PRIaTXN " (%s)", dbi, (int)kvx->name.iov_len,
-           (const char *)kvx->name.iov_base, txn->txnid, "wrong rec-size");
-    return MDBX_INCOMPATIBLE; /* not a named DB */
-  }
-
-  uint16_t flags = UNALIGNED_PEEK_16(data.iov_base, tree_t, flags);
+  const unsigned db_flags = UNALIGNED_PEEK_16(data.iov_base, tree_t, flags);
+  const pgno_t db_root_pgno = peek_pgno(ptr_disp(data.iov_base, offsetof(tree_t, root)));
  /* The txn may not know this DBI, or another process may
   * have dropped and recreated the DB with other flags. */
-  tree_t *const db = &txn->dbs[dbi];
-  if (unlikely((db->flags & DB_PERSISTENT_FLAGS) != flags)) {
+  if (unlikely((wanna_flags ^ db_flags) & DB_PERSISTENT_FLAGS) && !(wanna_flags & MDBX_DB_ACCEDE) &&
+      !((wanna_flags & MDBX_CREATE) && db_root_pgno == P_INVALID)) {
    NOTICE("dbi %zu refs to the re-created table `%.*s` for txn %" PRIaTXN
           " with different flags (present 0x%X != wanna 0x%X)",
-           dbi, (int)kvx->name.iov_len, (const char *)kvx->name.iov_base, txn->txnid, db->flags & DB_PERSISTENT_FLAGS,
-           flags);
-    return MDBX_INCOMPATIBLE;
+           dbi, (int)name->iov_len, (const char *)name->iov_base, txn->txnid, db_flags & DB_PERSISTENT_FLAGS,
+           wanna_flags & DB_PERSISTENT_FLAGS);
+    return MDBX_INCOMPATIBLE /* not a named DB */;
  }

+  tree_t *const db = &txn->dbs[dbi];
  memcpy(db, data.iov_base, sizeof(tree_t));
 #if !MDBX_DISABLE_VALIDATION
-  const txnid_t pp_txnid = couple.outer.pg[couple.outer.top]->txnid;
-  tASSERT(txn, txn->front_txnid >= pp_txnid);
-  if (unlikely(db->mod_txnid > pp_txnid)) {
-    ERROR("db.mod_txnid (%" PRIaTXN ") > page-txnid (%" PRIaTXN ")", db->mod_txnid, pp_txnid);
+  const txnid_t maindb_leafpage_txnid = mc->pg[mc->top]->txnid;
+  tASSERT(txn, txn->front_txnid >= maindb_leafpage_txnid);
+  if (unlikely(db->mod_txnid > maindb_leafpage_txnid)) {
+    ERROR("db.mod_txnid (%" PRIaTXN ") > page-txnid (%" PRIaTXN ")", db->mod_txnid, maindb_leafpage_txnid);
    return MDBX_CORRUPTED;
  }
 #endif /* !MDBX_DISABLE_VALIDATION */
-  rc = tbl_setup_ifneed(txn->env, kvx, db);
+
+  return MDBX_SUCCESS;
+}
+
+int tbl_create(MDBX_txn *txn, MDBX_cursor *mc, size_t slot, const MDBX_val *name, unsigned db_flags) {
+  tASSERT(txn, db_flags & MDBX_CREATE);
+  MDBX_val body;
+  body.iov_base = memset(&txn->dbs[slot], 0, body.iov_len = sizeof(tree_t));
+  txn->dbs[slot].root = P_INVALID;
+  txn->dbs[slot].mod_txnid = txn->txnid;
+  txn->dbs[slot].flags = db_flags & DB_PERSISTENT_FLAGS;
+  mc->next = txn->cursors[MAIN_DBI];
+  txn->cursors[MAIN_DBI] = mc;
+  int err = cursor_put_checklen(mc, name, &body, N_TREE | MDBX_NOOVERWRITE);
+  txn->cursors[MAIN_DBI] = mc->next;
+  if (likely(err == MDBX_SUCCESS)) {
+    txn->flags |= MDBX_TXN_DIRTY;
+    tASSERT(txn, (txn->dbi_state[MAIN_DBI] & DBI_DIRTY) != 0);
+  }
+  return err;
+}
+
+int tbl_refresh(MDBX_txn *txn, size_t dbi) {
+  cursor_couple_t couple;
+  kvx_t *const kvx = &txn->env->kvs[dbi];
+  int rc = tbl_fetch(txn, &couple.outer, dbi, &kvx->name, txn->dbs[dbi].flags);
+  if (likely(rc != MDBX_SUCCESS))
+    return dbi_gone(txn, dbi, rc);
+
+  rc = tbl_setup_ifneed(txn->env, kvx, &txn->dbs[dbi]);
  if (unlikely(rc != MDBX_SUCCESS))
-    return rc;
+    return dbi_gone(txn, dbi, rc);

  if (unlikely(dbi_changed(txn, dbi)))
    return MDBX_BAD_DBI;
--- a/src/tls.c
+++ b/src/tls.c
@@ -373,25 +373,27 @@ __cold static int rthc_drown(MDBX_env *const env) {
  int rc = MDBX_SUCCESS;
  MDBX_env *inprocess_neighbor = nullptr;
  if (likely(env->lck_mmap.lck && current_pid == env->pid)) {
-    reader_slot_t *const begin = &env->lck_mmap.lck->rdt[0];
-    reader_slot_t *const end = &env->lck_mmap.lck->rdt[env->max_readers];
-    TRACE("== %s env %p pid %d, readers %p ...%p, current-pid %d", (current_pid == env->pid) ? "cleanup" : "skip",
-          __Wpedantic_format_voidptr(env), env->pid, __Wpedantic_format_voidptr(begin), __Wpedantic_format_voidptr(end),
-          current_pid);
-    bool cleaned = false;
-    for (reader_slot_t *r = begin; r < end; ++r) {
-      if (atomic_load32(&r->pid, mo_Relaxed) == current_pid) {
-        atomic_store32(&r->pid, 0, mo_AcquireRelease);
-        TRACE("== cleanup %p", __Wpedantic_format_voidptr(r));
-        cleaned = true;
-      }
-    }
-    if (cleaned)
-      atomic_store32(&env->lck_mmap.lck->rdt_refresh_flag, true, mo_Relaxed);
    rc = rthc_uniq_check(&env->lck_mmap, &inprocess_neighbor);
-    if (!inprocess_neighbor && env->registered_reader_pid && env->lck_mmap.fd != INVALID_HANDLE_VALUE) {
-      int err = lck_rpid_clear(env);
-      rc = rc ? rc : err;
+    if (!inprocess_neighbor) {
+      reader_slot_t *const begin = &env->lck_mmap.lck->rdt[0];
+      reader_slot_t *const end = &env->lck_mmap.lck->rdt[env->max_readers];
+      TRACE("== %s env %p pid %d, readers %p ...%p, current-pid %d", (current_pid == env->pid) ? "cleanup" : "skip",
+            __Wpedantic_format_voidptr(env), env->pid, __Wpedantic_format_voidptr(begin),
+            __Wpedantic_format_voidptr(end), current_pid);
+      bool cleaned = false;
+      for (reader_slot_t *r = begin; r < end; ++r) {
+        if (atomic_load32(&r->pid, mo_Relaxed) == current_pid) {
+          atomic_store32(&r->pid, 0, mo_AcquireRelease);
+          TRACE("== cleanup %p", __Wpedantic_format_voidptr(r));
+          cleaned = true;
+        }
+      }
+      if (cleaned)
+        atomic_store32(&env->lck_mmap.lck->rdt_refresh_flag, true, mo_Relaxed);
+      if (env->registered_reader_pid && env->lck_mmap.fd != INVALID_HANDLE_VALUE) {
+        int err = lck_rpid_clear(env);
+        rc = rc ? rc : err;
+      }
    }
  }
  int err = lck_destroy(env, inprocess_neighbor, current_pid);
@@ -513,7 +515,9 @@ __cold void rthc_dtor(const uint32_t current_pid) {
    MDBX_env *const env = rthc_table[i].env;
    if (env->pid != current_pid)
      continue;
-    if (!(env->flags & ENV_TXKEY))
+    if (!env->lck_mmap.lck || env->lck_mmap.base == MAP_FAILED)
+      continue;
+    if (!(env->flags & ENV_TXKEY) || !env->lck_mmap.lck)
      continue;
    env->flags -= ENV_TXKEY;
    reader_slot_t *const begin = &env->lck_mmap.lck->rdt[0];
--- a/src/tools/chk.c
+++ b/src/tools/chk.c
@@ -414,7 +414,6 @@ int main(int argc, char *argv[]) {
  if (argc < 2)
    usage(prog);

-  double elapsed;
 #if defined(_WIN32) || defined(_WIN64)
  uint64_t timestamp_start, timestamp_finish;
  timestamp_start = GetMilliseconds();
@@ -652,23 +651,26 @@ bailout:

 #if defined(_WIN32) || defined(_WIN64)
  timestamp_finish = GetMilliseconds();
-  elapsed = (timestamp_finish - timestamp_start) * 1e-3;
+  const uint64_t elapsed_msec = (timestamp_finish - timestamp_start);
 #else
  if (clock_gettime(CLOCK_MONOTONIC, &timestamp_finish)) {
    error_fn("clock_gettime", errno);
    return EXIT_FAILURE_SYS;
  }
-  elapsed =
-      timestamp_finish.tv_sec - timestamp_start.tv_sec + (timestamp_finish.tv_nsec - timestamp_start.tv_nsec) * 1e-9;
+  const uint64_t elapsed_msec = UINT64_C(1000) * (timestamp_finish.tv_sec - timestamp_start.tv_sec) +
+                                (timestamp_finish.tv_nsec - timestamp_start.tv_nsec) / 1000000;
 #endif /* !WINDOWS */

+  const size_t elapsed_seconds = (size_t)(elapsed_msec / 1000u);
+  const size_t elapsed_mod_ms = (size_t)(elapsed_msec % 1000u);
  if (chk.result.total_problems) {
-    print_ln(MDBX_chk_result, "Total %" PRIuSIZE " error%s detected, elapsed %.3f seconds.", chk.result.total_problems,
-             (chk.result.total_problems > 1) ? "s are" : " is", elapsed);
+    print_ln(MDBX_chk_result, "Total %" PRIuSIZE " error%s detected, elapsed %zu.%03zu seconds.",
+             chk.result.total_problems, (chk.result.total_problems > 1) ? "s are" : " is", elapsed_seconds,
+             elapsed_mod_ms);
    if (chk.result.problems_meta || chk.result.problems_kv || chk.result.problems_gc)
      return EXIT_FAILURE_CHECK_MAJOR;
    return EXIT_FAILURE_CHECK_MINOR;
  }
-  print_ln(MDBX_chk_result, "No error is detected, elapsed %.3f seconds.", elapsed);
+  print_ln(MDBX_chk_result, "No error is detected, elapsed %zu.%03zu seconds.", elapsed_seconds, elapsed_mod_ms);
  return EXIT_SUCCESS;
 }
--- a/src/tools/stat.c
+++ b/src/tools/stat.c
@@ -341,8 +341,8 @@ int main(int argc, char *argv[]) {
    }
    print_stat(&mst);

-    pgno_t pages = 0, *iptr;
-    pgno_t reclaimable = 0;
+    size_t gc_pages = 0, *iptr;
+    size_t gc_reclaimable = 0;
    MDBX_val key, data;
    while (MDBX_SUCCESS == (rc = mdbx_cursor_get(cursor, &key, &data, MDBX_NEXT))) {
      if (user_break) {
@@ -352,9 +352,9 @@ int main(int argc, char *argv[]) {
      iptr = data.iov_base;
      const pgno_t number = *iptr++;

-      pages += number;
+      gc_pages += number;
      if (envinfo && mei.mi_latter_reader_txnid > *(txnid_t *)key.iov_base)
-        reclaimable += number;
+        gc_reclaimable += number;

      if (freinfo > 1) {
        char *bad = "";
@@ -402,36 +402,43 @@ int main(int argc, char *argv[]) {
    }

    if (envinfo) {
-      uint64_t value = mei.mi_mapsize / mei.mi_dxb_pagesize;
-      double percent = value / 100.0;
-      printf("Page Usage\n");
-      printf("  Total: %" PRIu64 " 100%%\n", value);
+      char buffer[64];

-      value = mei.mi_geo.current / mei.mi_dxb_pagesize;
-      printf("  Backed: %" PRIu64 " %.1f%%\n", value, value / percent);
+      puts("Page Usage");
+      const size_t total_pages = mei.mi_mapsize / mei.mi_dxb_pagesize;
+      printf("  Total: %" PRIuSIZE " 100%%\n", total_pages);

-      value = mei.mi_last_pgno + 1;
-      printf("  Allocated: %" PRIu64 " %.1f%%\n", value, value / percent);
+      const size_t backed_pages = mei.mi_geo.current / mei.mi_dxb_pagesize;
+      printf("  Backed: %" PRIuSIZE " %s%%\n", backed_pages,
+             mdbx_ratio2percents(backed_pages, total_pages, buffer, sizeof(buffer)));

-      value = mei.mi_mapsize / mei.mi_dxb_pagesize - (mei.mi_last_pgno + 1);
-      printf("  Remained: %" PRIu64 " %.1f%%\n", value, value / percent);
+      const size_t allocated_pages = mei.mi_last_pgno + 1;
+      printf("  Allocated: %" PRIuSIZE " %s%%\n", allocated_pages,
+             mdbx_ratio2percents(allocated_pages, total_pages, buffer, sizeof(buffer)));

-      value = mei.mi_last_pgno + 1 - pages;
-      printf("  Used: %" PRIu64 " %.1f%%\n", value, value / percent);
+      const size_t remained_pages = total_pages - allocated_pages;
+      printf("  Remained: %" PRIuSIZE " %s%%\n", remained_pages,
+             mdbx_ratio2percents(remained_pages, total_pages, buffer, sizeof(buffer)));

-      value = pages;
-      printf("  GC: %" PRIu64 " %.1f%%\n", value, value / percent);
+      const size_t used_pages = allocated_pages - gc_pages;
+      printf("  Used: %" PRIuSIZE " %s%%\n", used_pages,
+             mdbx_ratio2percents(used_pages, total_pages, buffer, sizeof(buffer)));

-      value = pages - reclaimable;
-      printf("  Retained: %" PRIu64 " %.1f%%\n", value, value / percent);
+      printf("  GC: %" PRIuSIZE " %s%%\n", gc_pages,
+             mdbx_ratio2percents(gc_pages, total_pages, buffer, sizeof(buffer)));

-      value = reclaimable;
-      printf("  Reclaimable: %" PRIu64 " %.1f%%\n", value, value / percent);
+      printf("  Reclaimable: %" PRIuSIZE " %s%%\n", gc_reclaimable,
+             mdbx_ratio2percents(gc_reclaimable, total_pages, buffer, sizeof(buffer)));

-      value = mei.mi_mapsize / mei.mi_dxb_pagesize - (mei.mi_last_pgno + 1) + reclaimable;
-      printf("  Available: %" PRIu64 " %.1f%%\n", value, value / percent);
+      const size_t gc_retained = gc_pages - gc_reclaimable;
+      printf("  Retained: %" PRIuSIZE " %s%%\n", gc_retained,
+             mdbx_ratio2percents(gc_retained, total_pages, buffer, sizeof(buffer)));
+
+      const size_t available_pages = gc_reclaimable + remained_pages;
+      printf("  Available: %" PRIuSIZE " %s%%\n", available_pages,
+             mdbx_ratio2percents(available_pages, total_pages, buffer, sizeof(buffer)));
    } else
-      printf("  GC: %" PRIaPGNO " pages\n", pages);
+      printf("  GC: %" PRIuSIZE " pages\n", gc_pages);
  }

  rc = mdbx_dbi_open(txn, table, MDBX_DB_ACCEDE, &dbi);
--- a/src/tree-search.c
+++ b/src/tree-search.c
@@ -39,7 +39,7 @@ __hot int tree_search(MDBX_cursor *mc, const MDBX_val *key, int flags) {

  const size_t dbi = cursor_dbi(mc);
  if (unlikely(*cursor_dbi_state(mc) & DBI_STALE)) {
-    err = tbl_fetch(mc->txn, dbi);
+    err = tbl_refresh_absent2baddbi(mc->txn, dbi);
    if (unlikely(err != MDBX_SUCCESS))
      goto bailout;
  }
--- a/src/txn-ro.c
+++ b/src/txn-ro.c
@@ -168,6 +168,15 @@ int txn_ro_end(MDBX_txn *txn, unsigned mode) {
      txn->ro.slot = nullptr;
    else {
      eASSERT(env, slot->pid.weak == env->pid);
+      if (unlikely(slot->pid.weak == 0)) {
+        txn->flags = MDBX_TXN_RDONLY | MDBX_TXN_FINISHED | MDBX_TXN_OUSTED;
+        txn->owner = 0;
+        if (mode & TXN_END_FREE) {
+          txn->signature = 0;
+          osal_free(txn);
+        }
+        return LOG_IFERR(MDBX_BAD_RSLOT);
+      }
      if (likely((txn->flags & MDBX_TXN_FINISHED) == 0)) {
        if (likely((txn->flags & MDBX_TXN_PARKED) == 0)) {
          ENSURE(env, txn->txnid >=
--- a/src/txn.c
+++ b/src/txn.c
@@ -47,7 +47,7 @@ int txn_shadow_cursors(const MDBX_txn *parent, const size_t dbi) {
    int err = cursor_shadow(cursor, txn, dbi);
    if (unlikely(err != MDBX_SUCCESS)) {
      /* не получилось забекапить курсоры */
-      txn->dbi_state[dbi] = DBI_OLDEN | DBI_LINDO | DBI_STALE;
+      txn->dbi_state[dbi] = DBI_OLDEN | DBI_LINDO;
      txn->flags |= MDBX_TXN_ERROR;
      return err;
    }
--- a/src/utils.c
+++ b/src/utils.c
@@ -41,3 +41,52 @@ MDBX_NOTHROW_CONST_FUNCTION uint64_t rrxmrrxmsx_0(uint64_t v) {
  v *= UINT64_C(0x9FB21C651E98DF25);
  return v ^ v >> 28;
 }
+
+__cold char *ratio2digits(const uint64_t v, const uint64_t d, ratio2digits_buffer_t *const buffer, int precision) {
+  assert(d > 0 && precision < 20);
+  char *const dot = buffer->string + 21;
+  uint64_t i = v / d, f = v % d, m = d;
+
+  char *tail = dot;
+  bool carry = m - f < m / 2;
+  if (precision > 0) {
+    *tail = '.';
+    do {
+      while (unlikely(f > UINT64_MAX / 10)) {
+        f >>= 1;
+        m >>= 1;
+      }
+      f *= 10;
+      assert(tail > buffer->string && tail < ARRAY_END(buffer->string) - 1);
+      *++tail = '0' + (char)(f / m);
+      f %= m;
+    } while (--precision && tail < ARRAY_END(buffer->string) - 1);
+
+    carry = m - f < m / 2;
+    for (char *scan = tail; carry && scan > dot; --scan)
+      *scan = (carry = *scan == '9') ? '0' : *scan + 1;
+  }
+  assert(tail > buffer->string && tail < ARRAY_END(buffer->string) - 1);
+  *++tail = '\0';
+
+  char *head = dot;
+  i += carry;
+  while (i > 9) {
+    assert(head > buffer->string && head < ARRAY_END(buffer->string));
+    *--head = '0' + (char)(i % 10);
+    i /= 10;
+  }
+  assert(head > buffer->string && head < ARRAY_END(buffer->string));
+  *--head = '0' + (char)i;
+
+  return head;
+}
+
+__cold char *ratio2percent(uint64_t value, uint64_t whole, ratio2digits_buffer_t *buffer) {
+  while (unlikely(value > UINT64_MAX / 100)) {
+    value >>= 1;
+    whole >>= 1;
+  }
+  const bool rough = whole >= value && (!value || value > whole / 16);
+  return ratio2digits(value * 100, whole, buffer, rough ? 1 : 2);
+}
--- a/src/utils.h
+++ b/src/utils.h
@@ -76,3 +76,10 @@ MDBX_MAYBE_UNUSED static inline uint64_t monotime_since_cached(uint64_t begin_ti
  }
  return cache->value - begin_timestamp;
 }
+
+typedef struct ratio2digits_buffer {
+  char string[1 + 20 + 1 + 19 + 1];
+} ratio2digits_buffer_t;
+
+char *ratio2digits(const uint64_t v, const uint64_t d, ratio2digits_buffer_t *const buffer, int precision);
+char *ratio2percent(const uint64_t v, const uint64_t d, ratio2digits_buffer_t *const buffer);
--- a/test/battery-tmux.sh
+++ b/test/battery-tmux.sh
@@ -8,7 +8,7 @@ DIR="$(dirname ${BASH_SOURCE[0]})"
 TEST="${DIR}/stochastic.sh --skip-make --db-upto-gb 32"
 PREFIX="/dev/shm/mdbxtest-"

-NUMACTL="$(which numactl 2>-)"
+NUMACTL="$(which numactl 2>&-)"
 NUMALIST=()
 NUMAIDX=0
 if [ -n "${NUMACTL}" -a $(${NUMACTL} --hardware | grep 'node [0-9]\+ cpus' | wc -l) -gt 1 ]; then
--- a/test/config.c++
+++ b/test/config.c++
@@ -3,10 +3,6 @@

 #include "test.h++"

-#if defined(_MSC_VER) && !defined(strcasecmp)
-#define strcasecmp(str, len) _stricmp(str, len)
-#endif /* _MSC_VER && strcasecmp() */
-
 namespace config {

 bool parse_option(int argc, char *const argv[], int &narg, const char *option, const char **value,
--- a/test/jitter.c++
+++ b/test/jitter.c++
@@ -22,9 +22,7 @@ void testcase_jitter::check_dbi_error(int expect, const char *stage) {

 bool testcase_jitter::run() {
  int err;
-  size_t upper_limit = config.params.size_upper;
-  if (upper_limit < 1)
-    upper_limit = config.params.size_now * 2;
+  size_t upper_limit = (config.params.size_upper < 1) ? config.params.size_now * 2 : config.params.size_upper;

  tablename_buf buffer;
  const char *const tablename = db_tablename(buffer);
--- a/test/osal-windows.c++
+++ b/test/osal-windows.c++
@@ -9,32 +9,15 @@ static std::unordered_map<unsigned, HANDLE> events;
 static HANDLE hBarrierSemaphore, hBarrierEvent;
 static HANDLE hProgressActiveEvent, hProgressPassiveEvent;

-static int waitstatus2errcode(DWORD result) {
-  switch (result) {
-  case WAIT_OBJECT_0:
-    return MDBX_SUCCESS;
-  case WAIT_FAILED:
-    return GetLastError();
-  case WAIT_ABANDONED:
-    return ERROR_ABANDONED_WAIT_0;
-  case WAIT_IO_COMPLETION:
-    return ERROR_USER_APC;
-  case WAIT_TIMEOUT:
-    return ERROR_TIMEOUT;
-  default:
-    return ERROR_UNHANDLED_ERROR;
-  }
-}
-
 void osal_wait4barrier(void) {
  DWORD rc = WaitForSingleObject(hBarrierSemaphore, 0);
  switch (rc) {
  default:
-    failure_perror("WaitForSingleObject(BarrierSemaphore)", waitstatus2errcode(rc));
+    failure_perror("WaitForSingleObject(BarrierSemaphore)", osal_waitstatus2errcode(rc));
  case WAIT_OBJECT_0:
    rc = WaitForSingleObject(hBarrierEvent, INFINITE);
    if (rc != WAIT_OBJECT_0)
-      failure_perror("WaitForSingleObject(BarrierEvent)", waitstatus2errcode(rc));
+      failure_perror("WaitForSingleObject(BarrierEvent)", osal_waitstatus2errcode(rc));
    break;
  case WAIT_TIMEOUT:
    if (!SetEvent(hBarrierEvent))
@@ -95,7 +78,7 @@ void osal_broadcast(unsigned id) {
 int osal_waitfor(unsigned id) {
  log_trace("osal_waitfor: event %u", id);
  DWORD rc = WaitForSingleObject(events.at(id), INFINITE);
-  return waitstatus2errcode(rc);
+  return osal_waitstatus2errcode(rc);
 }

 int osal_delay(unsigned seconds) {
@@ -397,7 +380,7 @@ int osal_actor_poll(mdbx_pid_t &pid, unsigned timeout) {
      return 0;
    }

-    return waitstatus2errcode(rc);
+    return osal_waitstatus2errcode(rc);
  }
 }

@@ -418,7 +401,7 @@ void osal_udelay(size_t us) {
    if (us > threshold_us && us > 1000) {
      DWORD rc = SleepEx(unsigned(us / 1000), TRUE);
      if (rc)
-        failure_perror("SleepEx()", waitstatus2errcode(rc));
+        failure_perror("SleepEx()", osal_waitstatus2errcode(rc));
      us = 0;
    }
Author	SHA1	Message	Date
Леонид Юрьев (Leonid Yuriev)	9d7c5243d2	mdbx: update ChangeLog.	2025-11-12 18:10:35 +03:00
Леонид Юрьев (Leonid Yuriev)	5b740913d0	mdbx++: add missing `std::hash<mdbx::buffer<>>`.	2025-11-12 17:54:57 +03:00
Леонид Юрьев (Leonid Yuriev)	2f33449f2a	mdbx-windows: use timeouts instead of retries for file locking.	2025-11-12 17:54:57 +03:00
Leonid Yuriev	aac890314c	mdbx-windows: refine assertion handling for debug builds.	2025-11-12 17:54:40 +03:00
Leonid Yuriev	cfb9a55ebc	mdbx: fix tls-dtor in case library unloading with an incomplete initialized env instance.	2025-11-10 21:38:06 +03:00
Леонид Юрьев (Leonid Yuriev)	cdbf2ed856	mdbx: update ChangeLog.	2025-11-08 00:25:04 +03:00
Леонид Юрьев (Leonid Yuriev)	f2f2cc3b40	mdbx: add workaround for ext4 fast-commit bug.	2025-11-07 21:17:18 +03:00
Леонид Юрьев (Leonid Yuriev)	3f8dad1ede	mdbx-test: minor fix jitter test internals.	2025-11-07 21:11:21 +03:00
Леонид Юрьев (Leonid Yuriev)	a17e041830	mdbx: refactoring fetch/refresh/create/open tables and DBI-handles. The (rare, quirky) scenario of recreating a previously opened and used table/DBI-handle after it has been deleted by another process is now supported.	2025-11-06 10:26:28 +03:00
Леонид Юрьев (Leonid Yuriev)	207fc11d76	mdbx: update ChangeLog.	2025-11-05 14:51:44 +03:00
Леонид Юрьев (Leonid Yuriev)	3813333b28	mdbx: clean reader locktable by `rthc_drown()` only when no inprocess-neighbor.	2025-11-05 14:51:44 +03:00
Леонид Юрьев (Leonid Yuriev)	7628369819	mdbx: fix dummy coverity-scan warning.	2025-11-05 14:51:44 +03:00
Леонид Юрьев (Leonid Yuriev)	3bec0dbc6e	mdbx: ending the transaction and return an error in case reader-slot was evicted.	2025-11-05 14:51:44 +03:00
Леонид Юрьев (Leonid Yuriev)	c07cfd30e1	mdbx: refine description of `MDBX_BAD_RSLOT`.	2025-11-05 14:51:44 +03:00
Леонид Юрьев (Leonid Yuriev)	ffb822cb61	mdbx: refine internal `env_info_sys()`.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	7f8e3c8781	mdbx: more refining chk-output.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	916e6e817d	mdbx: refine handling `sys_allocation_granularity`.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	bf3f9be98a	mdbx: using clang-format-22.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	7b112df36e	mdbx: fix `unused functions` warning from modern clang.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	4073330ad7	mdbx: patch update for older versions of buildroot.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	f525e4d292	mdbx: merge-in ChangeLog from the stable/0.13.x branch.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	baf3eb267f	mdbx: fix extra type-casting typo.	2025-11-05 01:20:10 +03:00
Леонид Юрьев (Leonid Yuriev)	0b24446e8e	mdbx: fix typo assertion-failure regression.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	8bd2ae9f20	mdbx: update ChangeLog.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	f488d84dc7	mdbx-cmake: cleanup from linking with `libm`.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	f695a1b48e	mdbx-make: cleanup from linking with `libm`.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	5fb45cb3c9	mdbx-make: add `-Wl,--as-needed'` to LDFLAGS.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	0838af8f3d	mdbx-tools: cleanup `mdbx_stat` from float-point.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	255a431bc1	mdbx-tools: cleanup `mdbx_chk` from float-point.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	dccc807aff	mdbx: add float-point-free `mdbx_ratio2percents()` and `mdbx_ratio2digits()` to API for tools.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	8b2aa9fb65	mdbx: add `getenv_bool()` and fetching debug-options from the process environment.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	0d9b59dda1	mdbx: add `osal_strcasecmp()` and `osal_strncasecmp()`.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	65184ff73b	mdbx: rework/refine chk reporting tree/pages/tables information (squashed).	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	b8f4d6ccdd	mdbx: rename "other" pages to "broken" in chk-output.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	c466dea250	mdbx: clean library core from using a float-point.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	1cf65cd880	mdbx: refine handling the `MDBX_WITHOUT_MSVC_CRT` option.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	7e43e14c7b	mdbx: more info-output from `mdbx_env_chk()`. Print system io-block size, unified-page-cache block size, space allocated for the dxb-file in a filesystem.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	410bbbd9a5	mdbx: extending `MDBX_envinfo`.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	06b6739e68	mdbx: fix assertion inside `gc_alloc_ex()`.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	045968b46a	mdbx: fix `txn_basis_snapshot()`.	2025-11-05 01:20:09 +03:00
Леонид Юрьев (Leonid Yuriev)	e292e8178c	mdbx: update ChangeLog.	2025-10-29 00:14:26 +03:00
Леонид Юрьев (Leonid Yuriev)	60d5ba9790	mdbx: minor workaround for HarmonyOS's bug. The libc from HarmonyOS SDK erroneously defines `EOWNERDEAD`, `_POSIX_THREAD_PROCESS_SHARED >= 200809` and `PTHREAD_MUTEX_ROBUST` but the same time doesn't provide `pthread_mutexattr_setrobust()` and `pthread_mutex_consistent()`. This commit add a minor workaround for such bug for successful building without explicitly defining `MDBX_LOCKING=2001`. Related to https://github.com/erthink/libmdbx/issues/285, https://github.com/vorot93/libmdbx-rs/issues/41, https://github.com/isar-community/isar-community/issues/28.	2025-10-29 00:10:06 +03:00
Leonid Yuriev	43c4503a77	mdbx: minor clean-up tautology in assertion.	2025-10-26 18:02:04 +03:00
Leonid Yuriev	aafe0f0fba	mdbx: use Windows10 SDK by default.	2025-10-26 18:02:04 +03:00
Леонид Юрьев (Leonid Yuriev)	dc5f119de1	mdbx-cmake: support of `MDBX_USE_FALLOCATE` for CMake and Conan.	2025-10-20 12:52:36 +03:00
Леонид Юрьев (Leonid Yuriev)	a14fe7f195	mdbx: append TODO.	2025-10-20 12:17:46 +03:00
Леонид Юрьев (Leonid Yuriev)	4d6eb8a959	mdbx: update ChangeLog.	2025-10-18 12:36:36 +03:00
Леонид Юрьев (Leonid Yuriev)	2b0bfb9eea	mdbx: revert/drop `MDBX_DBG_NOFALLOC_INCORE` and introduce `osal_fsetsize()`. This fixes regression after the `2a7f460345` as when a DXB file remains longer than necessary on Mac or Linux when building without `_GNU_SOURCE`.	2025-10-18 12:36:29 +03:00
Леонид Юрьев (Leonid Yuriev)	5f2f5f34e0	mdbx-tests: fix minor typo in the `battery-tmux` script.	2025-10-17 14:31:17 +03:00
Леонид Юрьев (Leonid Yuriev)	a52fba9dbc	mdbx: update ChangeLog.	2025-10-10 09:47:23 +03:00
Леонид Юрьев (Leonid Yuriev)	ee6a045f17	mdbx: add `MDBX_DBG_NOFALLOC_INCORE`. It is a workaround to sporadic test failures due to lack of space in tmpfs and/or free memory.	2025-10-09 23:26:18 +03:00
Леонид Юрьев (Leonid Yuriev)	ed2cb62f39	mdbx-doc: refine doxygen comments for `enum MDBX_debug_flags_t`.	2025-10-09 23:26:18 +03:00
Леонид Юрьев (Leonid Yuriev)	924581bdc8	mdbx: merge-in ChangeLog from the stable/0.13.x branch.	2025-09-18 09:21:46 +03:00
Stefan de Konink	19db693d00	Doc: add difference between mdbx_dbi_open and mdbx_dbi_open2	2025-09-16 13:42:59 +03:00
Леонид Юрьев (Leonid Yuriev)	48c3805a96	mdbx: update TODO.	2025-09-12 12:49:54 +03:00
Леонид Юрьев (Leonid Yuriev)	07b07e19b3	mdbx: update ChangeLog.	2025-09-11 20:16:08 +03:00
Леонид Юрьев (Leonid Yuriev)	bdbbf3db68	mdbx: fix rare/specific unexpected assertion failure `bmi > 0` on 32-bit debug builds.	2025-09-11 19:06:14 +03:00
Леонид Юрьев (Leonid Yuriev)	f2a5ca26a6	mdbx: using `atomic_yield()` inside `safe64_read()` retry loop.	2025-09-09 22:26:40 +03:00