diff --git a/src/core.c b/src/core.c
index fbbc16cd..69588301 100644
--- a/src/core.c
+++ b/src/core.c
@@ -8861,6 +8861,8 @@ static int txn_renew(MDBX_txn *txn, const unsigned flags) {
         (db_flags & DB_VALID) ? DBI_VALID | DBI_USRVALID | DBI_STALE : 0;
   }
   txn->mt_dbistate[MAIN_DBI] = DBI_VALID | DBI_USRVALID;
+  rc =
+      setup_dbx(&txn->mt_dbxs[MAIN_DBI], &txn->mt_dbs[MAIN_DBI], env->me_psize);
   txn->mt_dbistate[FREE_DBI] = DBI_VALID;
   txn->mt_front =
       txn->mt_txnid + ((flags & (MDBX_WRITEMAP | MDBX_RDONLY)) == 0);
@@ -14493,6 +14495,10 @@ __cold int mdbx_env_openW(MDBX_env *env, const wchar_t *pathname,
          env_pathname.ent_len * sizeof(pathchar_t));
   env->me_dbxs[FREE_DBI].md_cmp = cmp_int_align4; /* aligned MDBX_INTEGERKEY */
   env->me_dbxs[FREE_DBI].md_dcmp = cmp_lenfast;
+  env->me_dbxs[FREE_DBI].md_klen_max = env->me_dbxs[FREE_DBI].md_klen_min = 8;
+  env->me_dbxs[FREE_DBI].md_vlen_min = 4;
+  env->me_dbxs[FREE_DBI].md_vlen_max =
+      mdbx_env_get_maxvalsize_ex(env, MDBX_INTEGERKEY);
 
   /* Использование O_DSYNC или FILE_FLAG_WRITE_THROUGH:
    *
@@ -22152,15 +22158,27 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
   if (unlikely(!dbi))
     return rc;
 
+  void *clone = nullptr;
+  bool locked = false;
   if (unlikely((user_flags & ~DB_USABLE_FLAGS) != 0)) {
-  early_bailout:
+  bailout:
+    tASSERT(txn, MDBX_IS_ERROR(rc));
     *dbi = 0;
+    if (locked)
+      ENSURE(txn->mt_env,
+             osal_fastmutex_release(&txn->mt_env->me_dbi_lock) == MDBX_SUCCESS);
+    osal_free(clone);
     return rc;
   }
 
   rc = check_txn(txn, MDBX_TXN_BLOCKED);
   if (unlikely(rc != MDBX_SUCCESS))
-    goto early_bailout;
+    goto bailout;
+
+  if ((user_flags & MDBX_CREATE) && unlikely(txn->mt_flags & MDBX_TXN_RDONLY)) {
+    rc = MDBX_EACCESS;
+    goto bailout;
+  }
 
   switch (user_flags & (MDBX_INTEGERDUP | MDBX_DUPFIXED | MDBX_DUPSORT |
                         MDBX_REVERSEDUP | MDBX_ACCEDE)) {
@@ -22170,7 +22188,7 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
     __fallthrough /* fall through */;
   default:
     rc = MDBX_EINVAL;
-    goto early_bailout;
+    goto bailout;
 
   case MDBX_DUPSORT:
   case MDBX_DUPSORT | MDBX_REVERSEDUP:
@@ -22187,21 +22205,21 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
       table_name->iov_base == MDBX_PGWALK_MAIN) {
     rc = dbi_bind(txn, MAIN_DBI, user_flags, keycmp, datacmp);
     if (unlikely(rc != MDBX_SUCCESS))
-      goto early_bailout;
+      goto bailout;
     *dbi = MAIN_DBI;
     return rc;
   }
   if (table_name == MDBX_PGWALK_GC || table_name->iov_base == MDBX_PGWALK_GC) {
     rc = dbi_bind(txn, FREE_DBI, user_flags, keycmp, datacmp);
     if (unlikely(rc != MDBX_SUCCESS))
-      goto early_bailout;
+      goto bailout;
     *dbi = FREE_DBI;
     return rc;
   }
   if (table_name == MDBX_PGWALK_META ||
       table_name->iov_base == MDBX_PGWALK_META) {
     rc = MDBX_EINVAL;
-    goto early_bailout;
+    goto bailout;
   }
 
   MDBX_val key = *table_name;
@@ -22209,13 +22227,34 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
   if (key.iov_len > env->me_leaf_nodemax - NODESIZE - sizeof(MDBX_db))
     return MDBX_EINVAL;
 
-  if (txn->mt_dbxs[MAIN_DBI].md_cmp == NULL) {
+  /* Cannot mix named table(s) with DUPSORT flags */
+  if (unlikely(txn->mt_dbs[MAIN_DBI].md_flags & MDBX_DUPSORT)) {
+    if ((user_flags & MDBX_CREATE) == 0) {
+      rc = MDBX_NOTFOUND;
+      goto bailout;
+    }
+    if (txn->mt_dbs[MAIN_DBI].md_leaf_pages || txn->mt_dbxs[MAIN_DBI].md_cmp) {
+      /* В MAIN_DBI есть записи либо она уже использовалась. */
+      rc = MDBX_INCOMPATIBLE;
+      goto bailout;
+    }
+    /* Пересоздаём MAIN_DBI если там пусто. */
+    atomic_store32(&txn->mt_dbiseqs[MAIN_DBI], dbi_seq(env, MAIN_DBI),
+                   mo_AcquireRelease);
+    tASSERT(txn, txn->mt_dbs[MAIN_DBI].md_depth == 0 &&
+                     txn->mt_dbs[MAIN_DBI].md_entries == 0 &&
+                     txn->mt_dbs[MAIN_DBI].md_root == P_INVALID);
+    txn->mt_dbs[MAIN_DBI].md_flags &= MDBX_REVERSEKEY | MDBX_INTEGERKEY;
+    txn->mt_dbistate[MAIN_DBI] |= DBI_DIRTY;
+    txn->mt_flags |= MDBX_TXN_DIRTY;
     txn->mt_dbxs[MAIN_DBI].md_cmp =
         get_default_keycmp(txn->mt_dbs[MAIN_DBI].md_flags);
     txn->mt_dbxs[MAIN_DBI].md_dcmp =
         get_default_datacmp(txn->mt_dbs[MAIN_DBI].md_flags);
   }
 
+  tASSERT(txn, txn->mt_dbxs[MAIN_DBI].md_cmp);
+
   /* Is the DB already open? */
   MDBX_dbi scan, slot;
   for (slot = scan = txn->mt_numdbs; --scan >= CORE_DBS;) {
@@ -22229,7 +22268,7 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
                 key.iov_len)) {
       rc = dbi_bind(txn, scan, user_flags, keycmp, datacmp);
       if (unlikely(rc != MDBX_SUCCESS))
-        goto early_bailout;
+        goto bailout;
       *dbi = scan;
       return rc;
     }
@@ -22238,14 +22277,7 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
   /* Fail, if no free slot and max hit */
   if (unlikely(slot >= env->me_maxdbs)) {
     rc = MDBX_DBS_FULL;
-    goto early_bailout;
-  }
-
-  /* Cannot mix named table with some main-table flags */
-  if (unlikely(txn->mt_dbs[MAIN_DBI].md_flags &
-               (MDBX_DUPSORT | MDBX_INTEGERKEY))) {
-    rc = (user_flags & MDBX_CREATE) ? MDBX_INCOMPATIBLE : MDBX_NOTFOUND;
-    goto early_bailout;
+    goto bailout;
   }
 
   /* Find the DB info */
@@ -22253,37 +22285,36 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
   MDBX_cursor_couple couple;
   rc = cursor_init(&couple.outer, txn, MAIN_DBI);
   if (unlikely(rc != MDBX_SUCCESS))
-    goto early_bailout;
+    goto bailout;
   rc = cursor_set(&couple.outer, &key, &data, MDBX_SET).err;
   if (unlikely(rc != MDBX_SUCCESS)) {
     if (rc != MDBX_NOTFOUND || !(user_flags & MDBX_CREATE))
-      goto early_bailout;
+      goto bailout;
   } else {
     /* make sure this is actually a table */
     MDBX_node *node = page_node(couple.outer.mc_pg[couple.outer.mc_top],
                                 couple.outer.mc_ki[couple.outer.mc_top]);
     if (unlikely((node_flags(node) & (F_DUPDATA | F_SUBDATA)) != F_SUBDATA)) {
       rc = MDBX_INCOMPATIBLE;
-      goto early_bailout;
+      goto bailout;
     }
     if (!MDBX_DISABLE_VALIDATION && unlikely(data.iov_len != sizeof(MDBX_db))) {
       rc = MDBX_CORRUPTED;
-      goto early_bailout;
+      goto bailout;
     }
   }
 
   if (rc != MDBX_SUCCESS && unlikely(txn->mt_flags & MDBX_TXN_RDONLY)) {
     rc = MDBX_EACCESS;
-    goto early_bailout;
+    goto bailout;
   }
 
   /* Done here so we cannot fail after creating a new DB */
-  void *clone = nullptr;
   if (key.iov_len) {
     clone = osal_malloc(key.iov_len);
     if (unlikely(!clone)) {
       rc = MDBX_ENOMEM;
-      goto early_bailout;
+      goto bailout;
     }
     key.iov_base = memcpy(clone, key.iov_base, key.iov_len);
   } else
@@ -22292,9 +22323,9 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
   int err = osal_fastmutex_acquire(&env->me_dbi_lock);
   if (unlikely(err != MDBX_SUCCESS)) {
     rc = err;
-    osal_free(clone);
-    goto early_bailout;
+    goto bailout;
   }
+  locked = true;
 
   /* Import handles from env */
   dbi_import_locked(txn);
@@ -22311,15 +22342,15 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
                 key.iov_len)) {
       rc = dbi_bind(txn, scan, user_flags, keycmp, datacmp);
       if (unlikely(rc != MDBX_SUCCESS))
-        goto later_bailout;
-      *dbi = scan;
-      goto later_exit;
+        goto bailout;
+      slot = scan;
+      goto done;
     }
   }
 
   if (unlikely(slot >= env->me_maxdbs)) {
     rc = MDBX_DBS_FULL;
-    goto later_bailout;
+    goto bailout;
   }
 
   unsigned dbiflags = DBI_FRESH | DBI_VALID | DBI_USRVALID;
@@ -22336,9 +22367,8 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
     WITH_CURSOR_TRACKING(couple.outer,
                          rc = mdbx_cursor_put(&couple.outer, &key, &data,
                                               F_SUBDATA | MDBX_NOOVERWRITE));
-
     if (unlikely(rc != MDBX_SUCCESS))
-      goto later_bailout;
+      goto bailout;
 
     dbiflags |= DBI_DIRTY | DBI_CREAT;
     txn->mt_flags |= MDBX_TXN_DIRTY;
@@ -22352,31 +22382,28 @@ static int dbi_open(MDBX_txn *txn, const MDBX_val *const table_name,
   rc = dbi_bind(txn, slot, user_flags, keycmp, datacmp);
   if (unlikely(rc != MDBX_SUCCESS)) {
     tASSERT(txn, (dbiflags & DBI_CREAT) == 0);
-  later_bailout:
-    *dbi = 0;
-  later_exit:
-    osal_free(clone);
-  } else {
-    txn->mt_dbistate[slot] = (uint8_t)dbiflags;
-    txn->mt_dbxs[slot].md_name = key;
-    txn->mt_dbiseqs[slot].weak = env->me_dbiseqs[slot].weak =
-        dbi_seq(env, slot);
-    if (!(dbiflags & DBI_CREAT))
-      env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags | DB_VALID;
-    if (txn->mt_numdbs == slot) {
-      txn->mt_cursors[slot] = NULL;
-      osal_compiler_barrier();
-      txn->mt_numdbs = slot + 1;
-    }
-    if (env->me_numdbs <= slot) {
-      osal_memory_fence(mo_AcquireRelease, true);
-      env->me_numdbs = slot + 1;
-    }
-    *dbi = slot;
+    goto bailout;
   }
 
+  txn->mt_dbistate[slot] = (uint8_t)dbiflags;
+  txn->mt_dbxs[slot].md_name = key;
+  txn->mt_dbiseqs[slot].weak = env->me_dbiseqs[slot].weak = dbi_seq(env, slot);
+  if (!(dbiflags & DBI_CREAT))
+    env->me_dbflags[slot] = txn->mt_dbs[slot].md_flags | DB_VALID;
+  if (txn->mt_numdbs == slot) {
+    txn->mt_cursors[slot] = NULL;
+    osal_compiler_barrier();
+    txn->mt_numdbs = slot + 1;
+  }
+  if (env->me_numdbs <= slot) {
+    osal_memory_fence(mo_AcquireRelease, true);
+    env->me_numdbs = slot + 1;
+  }
+
+done:
+  *dbi = slot;
   ENSURE(env, osal_fastmutex_release(&env->me_dbi_lock) == MDBX_SUCCESS);
-  return rc;
+  return MDBX_SUCCESS;
 }
 
 static int dbi_open_cstr(MDBX_txn *txn, const char *name_cstr,