Tips performance under solaris

Hi,

I try postgresql V 7.1.2 under solaris 2.8 ( patch + the last version ) and i use directio implementation
for ufs .
Improved UFS Direct I/O Concurrency (Quick I/O Equivalent)
Solaris 8 1/01 update release allows concurrent read and write access to regular UFS files. As databases generally pre-allocate files and seldom extend them thereafter, the effects of this enhancement are seen during the normal database operations. The improvement brings I/O-bound database performance on a UFS file system to about 90% of raw partition access speeds.

When you mount an ufs partition,
just try this command in order to test directio:
mount -F ufs -o forcedirectio /dev/dsk/XXX /testdb

I try on the same machine 2 databases location :
One under partition with directio
One under normal ufs partition

I use the same postgresql.conf and with pgbench i obtain
this resulats:

Pgbench -c 4 -v -t 100 testdb ( directio ufs )
tps = 13.425330
tps = 13.626090

Pgbench -c 4 -v -t 100 testdb ( ufs )
tps = 30.052012
tps = 30.630632

If you interest with directio try this links :

http://gecitsolutions.systemnews.com/system-news/jobdir/submitted/2001.03/3076/3076.html
http://www.idg.net/crd_solaris_452714_102.html

Cheers,

PEJAC Pascal