It doesn't look like it's related to autovacuum. I re-ran the test against the two solaris boxes with autovacuum turned off and the results look about the same.
8.3.7 - Solaris 10 11/06 s10x_u3wos_10 X86
real 0m43.662s
user 0m0.001s
sys 0m0.003s
real 0m43.565s
user 0m0.001s
sys 0m0.003s
real 0m43.742s
user 0m0.001s
sys 0m0.003s
8.4rc1 - Solaris 10 11/06 s10x_u3wos_10 X86
real 0m59.304s
user 0m0.001s
sys 0m0.003s
real 0m58.653s
user 0m0.001s
sys 0m0.003s
real 1m0.253s
user 0m0.001s
sys 0m0.003s
8.3.7 - Solaris 10 8/07 s10x_u4wos_12b X86
real 0m38.981s
user 0m0.002s
sys 0m0.004s
real 0m39.879s
user 0m0.002s
sys 0m0.004s
real 0m39.111s
user 0m0.002s
sys 0m0.004s
8.4rc1 - Solaris 10 8/07 s10x_u4wos_12b X86
real 0m50.647s
user 0m0.002s
sys 0m0.004s
real 0m49.453s
user 0m0.002s
sys 0m0.004s
real 0m49.725s
user 0m0.002s
sys 0m0.004s
Alan
On Thu, Jun 18, 2009 at 3:39 PM, Tom Lane
<tgl@sss.pgh.pa.us> wrote:
>> I am unable to duplicate any slowdown on this test case.
> [ Kevin can ]
It'd be useful first off to figure out if it's a CPU or I/O issue.
Is there any visible difference in vmstat output? Also, try turning
off autovacuum in both cases, just to see if that's related.
regards, tom lane