lmdb を Homebrew, apk, dnf, MacPorts, Nix, pacman, zypper, apt でインストール

プロジェクトリンク

• ホームページ
• リポジトリ
• 上流ドキュメント
• パッケージマネージャページ

コマンドとエイリアス

• mdb_copy
• mdb_dump
• mdb_load
• mdb_stat

プロジェクトの歴史

The project grew out of OpenLDAP's need for a compact, fast storage engine. Symas describes LMDB as developed for OpenLDAP and emphasizes its memory-mapped design and very small object-code footprint. The OpenLDAP source documentation describes LMDB as a Btree-based database manager, loosely modeled on the Berkeley DB API but intentionally simplified by exposing the database through a memory map.

Early LMDB release history was tied to the OpenLDAP source tree and the library was renamed from libmdb to liblmdb during the 0.9 series. The public OpenLDAP tree remains the official source-control home, while lmdb.tech hosts generated API documentation from the same library interface.

採用の歴史

LMDB spread beyond OpenLDAP because it offered a permissively licensed embedded store with transactional semantics, reader concurrency, and simple deployment as ordinary files. Package managers expose it both as development headers/libraries and as standalone utilities, which is why distributions commonly package it under names such as lmdb or liblmdb-dev.

Its adoption has been strongest in systems software that wants an embedded key-value database without a separate server process. The OpenLDAP and Symas documentation both frame LMDB as a library-first project, while the Homebrew formula records the command-line utilities that make it convenient for database inspection, backup, and conversion.

使われ方

Developers normally link against liblmdb and use LMDB environments and transactions from application code. Operators and package users encounter the mdb_* tools: mdb_dump and mdb_load move database contents through portable dump formats, mdb_copy makes safe copies, and mdb_stat reports environment and database statistics.

LMDB is commonly chosen when a program needs fast local persistence with low operational overhead. Its memory-mapped model makes configuration mostly about database environment sizing and filesystem placement rather than running a daemon or maintaining credentials.

パッケージ好きにとっての重要性

LMDB is package-nerd material because it is small, old-school C infrastructure with a large blast radius: many higher-level systems can depend on the same tiny library. It also embodies a distinctive design tradeoff, preferring OS page-cache behavior and copy-on-write pages over a heavier database server architecture.

For package maintainers, LMDB matters because ABI compatibility, headers, and the mdb_* utilities are all useful separately. It is one of those packages that looks boring in a dependency graph until a storage engine, LDAP deployment, or language binding needs it.

タイムライン

• 2011: LMDB/MDB development becomes visible in the OpenLDAP source history.
• 2012: The 0.9 series renames libmdb to liblmdb.
• 2010s: Linux and Unix package managers adopt LMDB as both a library package and a utility package.
• 2020s: OpenLDAP GitLab and lmdb.tech remain the main official source and API documentation surfaces.

Related projects

• OpenLDAP is the parent project and original deployment driver for LMDB.
• Berkeley DB is the older embedded database API family that LMDB's documentation says it is loosely modeled on.
• Language bindings and wrappers expose LMDB to ecosystems such as Python, Go, Rust, Java, Ruby, and Node.js.

ソース

• https://git.openldap.org/openldap/openldap/-/blob/master/libraries/liblmdb/lmdb.h
• https://git.openldap.org/openldap/openldap/-/tree/mdb.master/libraries/liblmdb
• https://www.lmdb.tech/doc/
• https://www.symas.com/mdb
• source_facts.executables
• source_facts.package-manager