Re: How much expensive are row level statistics?

On Mon, Dec 12, 2005 at 01:33:27PM -0500, Merlin Moncure wrote:
> > 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.
>
> That approximately confirms my results, except that the penalty may even
> be a little bit higher in the worst-case scenario. Row level stats hit
> the hardest if you are doing 1 row at a time operations over a
> persistent connection.

That's basically how the application I tested works: it receives
data from a stream and performs whatever insert/update/delete
statements are necessary to update the database for each chunk of
data. Repeat a few thousand times.

--
Michael Fuhr