In fully synchronous mode, which is LMDB's default mode, everything is persisted upon commit. This is a memory-mapped database, not a main-memory/in-memory database. It is fully persistent to disk, it just so happens that it uses mmap() instead of read()/write() and a user-level page cache.
People are always confusing "memory-mapped" with "memory-only". LMDB is not a memory-only database.
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In fully synchronous mode, which is LMDB's default mode, everything is persisted upon commit. This is a memory-mapped database, not a main-memory/in-memory database. It is fully persistent to disk, it just so happens that it uses mmap() instead of read()/write() and a user-level page cache.
People are always confusing "memory-mapped" with "memory-only". LMDB is not a memory-only database.
http://www.openldap.org/lists/openldap-devel/201111/msg00064...
I guess (as i did) assumed it meant memory-mapped I/O as opposed to something like memory-mapped file I/O or port mapping.