Re: OSDL DBT-2 w/ PostgreSQL 7.3.4 and 7.4beta5
Mark Wong <markw@osdl.org>
From: Mark Wong <markw@osdl.org>
To: Rod Taylor <rbt@rbt.ca>
Cc: PostgreSQL Development <pgsql-hackers@postgresql.org>, OSDL - DB General <osdldbt-general@lists.sourceforge.net>
Date: 2003-11-17T23:04:47Z
Lists: pgsql-hackers
On Sun, Nov 02, 2003 at 07:25:38AM -0500, Rod Taylor wrote: > On Sat, 2003-11-01 at 20:58, Mark Wong wrote: > > I don't remember making a conscious decision between the number and integer > > database type. Is that a significant oversight on my part? > > Numerics do exact math with support for arbitrary numbers. Unlike > Oracle, PostgreSQL does not retype NUMBER to a faster type internally > (like int). > > You may find a good sized improvement (possibly as much as 15%) by > switching to integer as it will both reduce CPU load and storage > requirements. I've changed all the numerics to integers and reals, where it was appropriate to maintain the precision specificed in the TPC-C spec. Here's a comparison of results: http://developer.osdl.org/markw/dbt2-pgsql/214/ - using all numerics - metric 1831.78 http://developer.osdl.org/markw/dbt2-pgsql/217/ - integers and reals where appropriate - metric 1972.94 Looks like I see about an 8% improvement in the metric with this instance. A definite decrease in user time in the processor utilization chart, which I presume is attributed to the 70% decrease in ticks to SearchCatCache in the database as reported by oprofile. Can anyone explain that one? Mark