wal_buffer tests in

Folks,

I ran a wal_buffer test series.   It appears that increasing the
wal_buffers is indeed very important for OLTP applications, potentially
resulting in as much as a 15% average increase in transaction processing.
What's interesting is that this is not just true for 8.1, it's true for
8.0.3 as well.

More importantly, 8.1 performance is somehow back up to above-8.0 levels.
Something was broken in June that's got fixed (this test series is based
on July 3 CVS) but I don't know what.  Clues?

Test results are here:
http://pgfoundry.org/docman/view.php/1000041/79/wal_buffer_test.pdf

As always, detailed test results are available from OSDL, just use:
http://khack.osdl.org/stp/#
where # is the test number.

--
--Josh

Josh Berkus
Aglio Database Solutions
San Francisco