dw/py-lmdb — pull request #64 by smartkiwi (2014-05-07 19:52:57+00:00)
Title: Adding NOLOCK flag to lmdb.open

LMDB mdb_env_open() has MDB_NOLOCK flag - that prevents lmdb from using lock:
Don't do any locking. If concurrent access is anticipated, the caller must manage all concurrency itself. For proper operation the caller must enforce single-writer semantics, and must ensure that no readers are using old transactions while a writer is active. The simplest approach is to use an exclusive lock so that no readers may be active at all when a writer begins.
My use case: I'm using lmdb as a readonly database that is accessed by 16 parallel processes at the same time and trying to avoid any possible overhead.