Hi Tom, Kevin, >> I have a query which is running slowly, and the query plan shows an > unexpected sequence scan where I'd have expected the planner to use an > index. Setting enable_seqscan=off causes the planner to use the index as > expected. > > That hashjoin plan doesn't look at all unreasonable to me. The fact > that it actually comes out a lot slower than the nestloop with inner > indexscan suggests that you must be running with the large table > completely cached in RAM. If that's the normal state of affairs for your > database, you should consider decreasing the random_page_cost setting > so that the planner will plan appropriately. >
A very quick test of the settings that Kevin posted produce a much better plan and faster response to that query (at least on my dev machine) I'll read up more on those settings before changing production, but it looks good - thanks very much! Cheers, Dan -- Dan Fairs | dan.fa...@gmail.com | www.fezconsulting.com
