Re: [HACKERS] [PATCHES] Last infomask bit

Tom Lane wrote:
> Bruce Momjian <bruce(at)momjian(dot)us> writes:
>> Tom Lane wrote:
>>> Has anyone bothered to measure the overhead added by having to mask to
>>> fetch or store the natts value? This is not a zero-cost improvement.
>
>> Tom, how should this be tested? I assume some loop of the same query
>> over and over again.
>
> I'd be satisfied by a demonstration of no meaningful difference in
> pgbench numbers.

I ran pgbench on CVS checkout taken before the patch was applied, and I
couldn't measure a difference.

I got 1329-1340 TPM from three runs both with and without the patch. The
tests were run on my laptop, with scaling factor 10, using "pgbench
postgres -t 100000 -v", with fsync and full_page_writes disabled to make
it CPU bound, while observing top to confirm that CPU usage was 100%
during the test.

I think that's enough performance testing for this patch.

--
Heikki Linnakangas
EnterpriseDB http://www.enterprisedb.com