"Bob Duffey" <bobduffey68@xxxxxxxxx> writes: > 2008/6/28 Steve Atkins <steve@xxxxxxxxxxx>: >> If you're iterating through the records with a cursor, the plan may >> be different, IIRC - weighted to provide first row quickly, as opposed >> to the query that was run that's weighted to provide last row quickly. >> > I agree, and I was hoping that would be the case, but as it happens it > wasn't. The planner does in fact pay more attention to first-row cost than total cost when given a DECLARE CURSOR instead of a regular SELECT. Apparently that wasn't enough to make the indexscan be preferred, though, which is a bit curious. You might want to look at effective_cache_size as well as random_page_cost. regards, tom lane
