[PERFORM] Update on putting WAL on ramdisk/
Some arbitrary data processing job WAL on single drive: 7.990 rec/s WAL on 2nd IDE drive: 8.329 rec/s WAL on tmpfs: 13.172 rec/s A huge jump in performance but a bit scary having a WAL that can disappear at any time. I'm gonna workup a rsync script and do some power-off experiments to see how badly it gets mangled. This could be good method though when you're dumping and restore an entire DB. Make a tmpfs mount, restore, shutdown DB and then copy the WAL back to the HD. I checked out the SanDisk IDE FlashDrives. They have a write cycle life of 2 million. I'll explore more expensive solid state drives. ---(end of broadcast)--- TIP 8: explain analyze is your friend
Re: [PERFORM] Update on putting WAL on ramdisk/
WAL on single drive: 7.990 rec/s WAL on 2nd IDE drive: 8.329 rec/s WAL on tmpfs: 13.172 rec/s A huge jump in performance but a bit scary having a WAL that can disappear at any time. I'm gonna workup a rsync script and do some power-off experiments to see how badly it gets mangled. Surely this is just equivalent to disabling fsync? If you put a WAL on a volatile file system, there's not a whole lot of point in having one at all. Russ Garrett[EMAIL PROTECTED] http://last.fm ---(end of broadcast)--- TIP 4: Don't 'kill -9' the postmaster
Re: [PERFORM] Update on putting WAL on ramdisk/
Russell Garrett wrote: WAL on single drive: 7.990 rec/s WAL on 2nd IDE drive: 8.329 rec/s WAL on tmpfs: 13.172 rec/s A huge jump in performance but a bit scary having a WAL that can disappear at any time. I'm gonna workup a rsync script and do some power-off experiments to see how badly it gets mangled. Surely this is just equivalent to disabling fsync? If you put a WAL on a volatile file system, there's not a whole lot of point in having one at all. These tests were all with fsync off. And no, it's not equivalent to fsync off since the WAL is always written immediately regardless of fsync setting. ---(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
