On Tue, 14 Oct 2003, Wei Weng wrote: > On Sat, 11 Oct 2003, Christopher Kings-Lynne wrote: > > > > > > I have two very similar queries which I need to execute. They both have > > > exactly the same from / where conditions. When I execute the first, it takes > > > about 16 seconds. The second is executed almost immediately after, it takes > > > 13 seconds. In short, I'd like to know why the query result isn't being > > > cached and any ideas on how to improve the execution. > > > > <snip> > > > > > OK - so I could execute the query once, and get the maximum size of the > > > array and the result set in one. I know what I am doing is less than optimal > > > but I had expected the query results to be cached. So the second execution > > > would be very quick. So why aren't they ? I have increased my cache size - > > > shared_buffers is 2000 and I have doubled the default max_fsm... settings > > > (although I am not sure what they do). sort_mem is 8192. > > > > PostgreSQL does not have, and has never had a query cache - so nothing > > you do is going to make that second query faster. > > > > Perhaps you are confusing it with the MySQL query cache? > > > > Chris > > > Is there plan on developing one (query cache)?
Not really, Postgresql's design makes it a bit of a non-winner. ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster