Re: 8.2 is 30% better in pgbench than 8.3 - Mailing list pgsql-hackers

From Greg Smith
Subject Re: 8.2 is 30% better in pgbench than 8.3
Date
Msg-id Pine.GSO.4.64.0707220134200.20660@westnet.com
Whole thread Raw
In response to Re: 8.2 is 30% better in pgbench than 8.3  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: 8.2 is 30% better in pgbench than 8.3  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
On Sat, 21 Jul 2007, Tom Lane wrote:

> With autovac off I see 8.3 as faster than 8.2 in pgbench.

Indeed.  I'm seeing much better pgbench results from HEAD than 8.2 when I 
set the configurations up identically.  I'm hoping to have a comparison 
set to show everyone this week.

> and use -t at least 1000 or so (otherwise startup transients are 
> significant).

I personally consider any pgbench run that lasts less than several minutes 
noise.  On a system that hits 500 TPS like Pavel's, I'd want to see around 
100,000 transactions before I consider the results significant.  And then 
I'd want a set of 3 at each configuration because even with longer runs, 
you occasionally get really odd results.  Until you have 3 it can be 
unclear which is the weird one.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD


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