> I ended up going back to a default postgresql.conf and reapplying the
> various tunings one-by-one. Turns out that while setting fsync = false
> had little effect on the slow IDE box, it had a drastic effect on this
> faster SCSI box and performance is quite acceptable now (aside from the
> expected falloff of about 30% after the first twenty minutes, which I
> believe comes from growing and shrinking tables without vacuumdb
> --analyzing).
Hmm. I wonder if that could be related to the issue where many IDE drives have write-caching enabled. With the write
cacheenabled
fsyncs are nearly immediate, so setting fsync=false makes little difference...