LMDB

Spec sheet

Purpose

LMDB is an ultra-fast, ultra-compact, crash-proof key-value embedded data store developed for the OpenLDAP Project.Read 1 Oct 2026 · symas.com

Integrations

Symas reports integrations with OpenDKIM, Heimdal Kerberos, Postfix, Cyrus SASL, MemcacheDB, SQLite3, and Riak.Read 1 Oct 2026 · symas.com

Support

Symas offers fixed-price Gold or Enterprise source-level support and porting or professional services for LMDB users.Read 1 Oct 2026 · symas.com

License

Symas states that LMDB is part of OpenLDAP and is under the OpenLDAP license, basically a BSD-style license.Read 1 Oct 2026 · symas.com

Headquarters

Grand Junction, Colorado, USARead 28 Sep 2026 · symas.com

Code size

LMDB is about 32KB of object code.Read 1 Oct 2026 · symas.com

Concurrency

Readers do not block writers, writers do not block readers, and multiple processes can open the same environment on one host.Read 1 Oct 2026 · symas.com

Data model

Keys are always sorted, making range lookups straightforward and efficient.Read 1 Oct 2026 · symas.com

Language support

Symas reports support for C, C++, Perl, Python, PHP, and other programming languages.Read 1 Oct 2026 · symas.com

Maintenance

LMDB requires no external process, background cleanup, compaction, application-level cache, logs, or crash-recovery procedure.Read 1 Oct 2026 · symas.com

Persistence

Memory-mapped files provide read performance comparable to an in-memory database while retaining disk persistence.Read 1 Oct 2026 · symas.com

Source availability

Development occurs in the OpenLDAP Project git repository and a clone is available on GitHub.Read 1 Oct 2026 · symas.com

Sub-databases

LMDB supports multiple sub-databases with transactions covering all sub-databases in an environment.Read 1 Oct 2026 · symas.com

Transactions

LMDB provides full ACID semantics with MVCC, reader/writer transactions, and deadlock-free serialized writes.Read 1 Oct 2026 · symas.com

Utilities

LMDB includes mdb_stat for database status, mdb_copy for complete backups, and complete API documentation.Read 1 Oct 2026 · symas.com

Zero-copy access

LMDB uses memory-mapped files for zero-copy lookup and iteration and uses the operating system buffer cache.Read 1 Oct 2026 · symas.com

Plans and prices

Every LMDB plan and price →

Where Specifiction places it

• Embedded Databases#22 of 307.5