Re: How much expensive are row level statistics?

Michael Fuhr wrote:
> On Sun, Dec 11, 2005 at 11:53:36AM +0000, Carlos Benkendorf wrote:
> > I would like to use autovacuum but is not too much expensive
> > collecting row level statistics?
>
> The cost depends on your usage patterns.  I did tests with one of
> my applications and saw no significant performance difference for
> simple selects, but a series of insert/update/delete operations ran
> about 30% slower when block- and row-level statistics were enabled
> versus when the statistics collector was disabled.

This series of i/u/d operations ran with no sleep in between, right?
I wouldn't expect a normal OLTP operation to be like this.  (If it is
you have a serious shortage of hardware ...)

--
Alvaro Herrera                                http://www.CommandPrompt.com/
PostgreSQL Replication, Consulting, Custom Development, 24x7 support