Mohan,
> I am looking at good rules to use for memory, WAL, SQL Transaction
> Isolation Levels and cache configuration along with anything else
> that I have missed.
http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html
For anything beyond that, you're asking for a service I charge $155/hour
for ....
--
-Josh Berkus
Aglio Database Solutions
San Francisco