Re: Guideline on use of temporary tables

Jimmy Choi wrote:
> I would like to use temporary table as a caching mechanism to speed up
> queries within the same session.

> Is this what temporary table is designed for? Are there caveats that I
> should be aware of? Can you think of other better alternatives?

It's a very common usage of temporary tables. Another is when loading
data that you want to process / split up.

Bear in mind that a temporary table is private to a particular backend,
so if you had 100 connections all using a temporary table for the same
query, that could be 100 copies of the data - not necessarily a
performance improvement.

Also, temporary tables have real entries in the system-tables, so make
sure autovacuum (or your manual vacuums) are scanning pg_class etc often
enough.

--
   Richard Huxton
   Archonet Ltd