Re: bad performance on Solaris 10

> > > Doing what http://blogs.sun.com/roller/page/jkshah suggests:
> > > wal_sync_method = fsync (unchanged)
> > > wal_buffers = 128 (was 8)
> > > checkpoint_segments = 128 (was 3)
> > > bgwriter_all_percent = 0 (was 0.333)
> > > bgwriter_all_maxpages = 0 (was 5)
> > > and leaving everything else default (solarispackages from pgfoundry)
> > > increased performance ~ 7 times!

Ok, so I could quite believe my own benchmarks and I decided
to do a fresh initdb and retry everything.

At first it looked like I coudn't reproduce the speed up I just saw.

Then I realized it was the
wal_sync_method = fsync
line that makes all the difference!

Normally parameters that are commented are default values, but for
wal_sync_method it actually says (note the comment):

wal_sync_method = fsync # the default is the first option
# supported by the operating system:
# open_datasync
# fdatasync
# fsync
# fsync_writethrough
# open_sync

So Im my last mail I drew the wrong conclusion, because i didn't comment
wal_sync_method to double check.

To the point: the default wal_sync_method choosen on Solaris 10 appears
to be a very bad one - for me, picking fsync increases performance ~
times 7, all other parameters unchanged!

Would it be a good idea to change this in the default install?

Bye, Chris.

PS: yes I did a fresh initdb again to double check ;)