Re: performance of count(*)

On Fri, May 06, 2011 at 03:43:02PM -0600, Scott Ribe wrote:

> In this case, it depends on the result of a pretty complex join that
> involves some gnarly time calculations, and finding the unmatched
> rows from one side of an outer join.

Yeah, in that case the HOT suggestions are very important.  I strongly
recomment you experiment in a test system with real data and
pathological cases in particular, in order to see what happens when
the outlier cases inevitably, Murphy willing, crop up.  That's not to
say you should arrange your plans for them, but forewarned is
forearmed.

A


--
Andrew Sullivan
ajs@crankycanuck.ca