(ITS#8191) mdb_txn_commit(empty txn) does not sync

Full_Name: Hallvard B Furuseth Version: LMDB_0.9.15 OS: URL: Submission from: (NULL) (81.191.45.5) Submitted by: hallvard

mdb_txn_commit(txn which made no changes) does not mdb_env_sync(), but lmdb.h says several times that Commit flushes buffers to disk.

My feeling is that this is a quirk the user should not need to know about, and it's cleaner to sy r rather than to document it.

OTOH I don't know if "fast commit of no-change txns" is a feature which someone expects to work, and if sync can be expensive even when there is no new data to flush. (I don't know what BDB does.)