Spiegelberg, Greg wrote:
We have a query which generates a small set of rows (~1,000) which are to be used in a DELETE on the same table. The problem we have is that we need to join on 5 different columns and it takes far too long.
You may have encountered the same problem I did: You *must* run ANALYZE on a temporary table before you use in another query. It's surprising that this is true even for very small tables (a few hundred to a few thousand rows), but it is. I had a case where I created a "scratch" table like yours, and the before/after ANALYZE performance was the difference between 30 seconds and a few milliseconds for the same query. Craig
