ISAR/libmdbx
3
0
Fork 0
mirror of https://github.com/isar/libmdbx.git synced 2024-12-30 02:34:13 +08:00
Code Issues Packages Projects Releases Wiki Activity

mdbx-doc: actualize key size limits.

Browse Source
This commit is contained in:
Leonid Yuriev 2021-05-09 23:29:55 +03:00
parent aa1f6fbd5f
commit 0a28b28da3
1 changed files with 4 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
README.md
View File

@ -154,8 +154,8 @@ transaction journal. No crash recovery needed. No maintenance is required.
## Limitations
- **Page size**: a power of 2, minimum `256` (mostly for testing), maximum `65536` bytes, default `4096` bytes.
- **Key size**: minimum `0`, maximum ≈¼ pagesize (`1348` bytes for default 4K pagesize, `21828` bytes for 64K pagesize).
- **Value size**: minimum `0`, maximum `2146435072` (`0x7FF00000`) bytes for maps, ≈¼ pagesize for multimaps (`1348` bytes for default 4K pagesize, `21828` bytes for 64K pagesize).
- **Key size**: minimum `0`, maximum ≈½ pagesize (`2022` bytes for default 4K pagesize, `32742` bytes for 64K pagesize).
- **Value size**: minimum `0`, maximum `2146435072` (`0x7FF00000`) bytes for maps, ≈½ pagesize for multimaps (`2022` bytes for default 4K pagesize, `32742` bytes for 64K pagesize).
- **Write transaction size**: up to `1327217884` pages (`4.944272` TiB for default 4K pagesize, `79.108351` TiB for 64K pagesize).
- **Database size**: up to `2147483648` pages (≈`8.0` TiB for default 4K pagesize, ≈`128.0` TiB for 64K pagesize).
- **Maximum sub-databases**: `32765`.
@ -200,8 +200,8 @@ the user's point of view.
## Added Features
1. Keys could be more than 2 times longer than _LMDB_.
> For DB with default page size _libmdbx_ support keys up to 1300 bytes
> and up to 21780 bytes for 64K page size. _LMDB_ allows key size up to
> For DB with default page size _libmdbx_ support keys up to 2022 bytes
> and up to 32742 bytes for 64K page size. _LMDB_ allows key size up to
> 511 bytes and may silently loses data with large values.
2. Up to 30% faster than _LMDB_ in [CRUD](https://en.wikipedia.org/wiki/Create,_read,_update_and_delete) benchmarks.