On Sun, 2006-04-30 at 22:14 -0700, Mark Wong wrote: > I would have gotten this out sooner but I'm having trouble with our > infrastructure. Here's a link to a table of data I've started putting > together regarding XLOG_BLCKSZ and wal_buffers on a 4-way Opteron > system: > http://developer.osdl.org/markw/pgsql/xlog_blcksz.html > > There are a couple of holes in the table but I think it shows enough > evidence to say that with dbt2 having a larger XLOG_BLCKSZ improves the > overall throughput of the test. > > I'm planning on continuing to increase XLOG_BLCKSZ and wal_buffers to > determine when the throughput starts to level out or drop off, and then > start experimenting with varying BLCKSZ. Let me know if there are other > things that would be more interesting to experiment with first.
IMHO you should be testing with higher wal_buffers settings. ISTM likely that the improved performance is due to there being more buffer space, rather than actually improving I/O. Setting wal_buffers to something fairly high say 4096 would completely remove any such effect so we are left with a view on the I/O. -- Simon Riggs EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
