Re: database performance and query performance question

Dan,

> Something that I do not understand is why if you use a valid_time =
> '2004-01-22 00:00:00' the query will use the index but if you do a
> valid_time >  '2004-01-22 00:00:00' it does not use the index?

Because of the expected number of rows to be returned.  Take a look at the row 
estimates on the forecastleelement scans.   

You can improve these estimates by increasing the ANALYZE stats and/or running 
ANALYZE more often.   Of course, increasing the stats makes analyze run 
slower ...

-- 
-Josh Berkus
 Aglio Database Solutions
 San Francisco