Magnus prepared a trivial patch which added the O_SYNC flag for windows and mapped it to FILE_FLAG_WRITE_THROUGH in win32_open.c. We pg_benched it and here are the results of our test on my WinXP workstation on a 10k raptor:
Settings were pgbench -t 100 -c 10. fsync = off: ~ 280 tps fsync on, WAL=fsync: ~ 35 tps fsync on, WAL=open_sync write cache policy on: ~ 240 tps fsync on, WAL=open_sync write cache policy off: ~ 80 tps 80 tps, btw, is about the results I'd expect from linux on this hardware. Also, the open_sync method plays much nicer with RAID devices, but it would need some more rigorous testing before I'd personally certify it as safe. As an aside, it doesn't look like the open_sync can be trusted with write caching policy on the disk (the default), and that's worth noting. Merlin ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
