Thanks Ragnar. That solved the problem. I still would like some explanation about this voodoo. Most importantly, how can I estimage a "good" statistics number? thanks, Eugene --- Dr NoName <spamacct11@xxxxxxxxx> wrote: > > the seqscan is cheaper when a large enough > > proportion > > (maybe 5%) of rows are retrieved, and indeed the > > cost > > is estimated at 39014 > > very good explanation. thank you. > > > > try to increase statistics for this column: > > > > ALTER TABLE render ALTER COLUMN person_id > > SET STATISTICS 1000; > > ANALYZE render; > > > > 1000 is the maximum value, and probably overkill, > > but you might start with that. If this helps, you > > can > > try to lower values until you find the lowest one > > that still suits your data. Usually, 200 is > enough. > > > ok, we're getting into voodoo territory. What is > this > "statistics"? How can I see what the current value > is? > How can I estimate what's a "good" value? Where can > I > find more information about this? > > thanks, > > Eugene > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam > protection around > http://mail.yahoo.com > > ---------------------------(end of > broadcast)--------------------------- > TIP 9: In versions below 8.0, the planner will > ignore your desire to > choose an index scan if your joining column's > datatypes do not > match > ____________________________________________________ Start your day with Yahoo! - make it your home page http://www.yahoo.com/r/hs ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
