Curtis Faith wrote: > Bruce Momjian wrote: > > I may be missing something here, but other backends don't block while > > one writes to WAL. > > I don't think they'll block until they get to the fsync or XLogWrite > call while another transaction is fsync'ing. > > I'm no Unix filesystem expert but I don't see how the OS can > handle multiple writes and fsyncs to the same file descriptors without > blocking other processes from writing at the same time. It may be that > there are some clever data structures they use but I've not seen huge > praise for most of the file systems. A well written file system could > minimize this contention but I'll bet it's there with most of the ones > that PostgreSQL most commonly runs on. > > I'll have to write a test and see if there really is a problem.
Yes, I can see some contention, but what does aio solve? -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly
