Kurt Roeckx wrote: > Here are my results on Linux 2.6.1 using cvs version 1.7. > > Those times with > 20 seconds, you really hear the disk go crazy. > > And I have the feeling something must be wrong. Those results > are reproducible. >
Wow, your O_SYNC times are great. Where can I buy some? :-) Anyway, we do need to find a way to test this because obviously there is huge platform variability. --------------------------------------------------------------------------- > > Kurt > > > Simple write timing: > write 0.139558 > > Compare fsync times on write() and non-write() descriptor: > (If the times are similar, fsync() can sync data written > on a different descriptor.) > write, fsync, close 8.249364 > write, close, fsync 8.356813 > > Compare one o_sync write to two: > one 16k o_sync write 28.487650 > two 8k o_sync writes 2.310304 > > Compare file sync methods with one 8k write: > (o_dsync unavailable) > open o_sync, write 1.010688 > write, fdatasync 25.109604 > write, fsync, 26.051218 > > Compare file sync methods with 2 8k writes: > (The fastest should be used for wal_sync_method) > (o_dsync unavailable) > open o_sync, write 2.212223 > write, fdatasync 27.439907 > write, fsync, 27.772294 > > > ---------------------------(end of broadcast)--------------------------- > TIP 5: Have you checked our extensive FAQ? > > http://www.postgresql.org/docs/faqs/FAQ.html > -- 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 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
