The Lightning Memory-Mapped Database (LMDB) is a new database library written by Symas Corp. for the OpenLDAP Project. LMDB is a highly optimized B+tree implementation that is orders of magnitude faster and more efficient than everything else in the software world. Reads scale perfectly linearly across arbitrarily many CPUs with no bottlenecks, and data is returned with zero memcpy's. Writes are on average twenty times faster than commonly available databases such as SQLite. The entire library compiles down to only 32K of object code, allowing it to execute completely inside a typical CPU's L1 cache. Backends for OpenLDAP slapd, Cyrus SASL, Heimdal, SQLite, OpenDKIM and many other projects have already been written.
This talk gives an overview of the library design, example code, and operational results of using LMDB in various projects.