On Tuesday 27 November 2007 09:33:36 cluster wrote: > I have a query that takes about 7000 ms in average to complete the first > time it runs. Subsequent runs complete in only 50 ms. That is more than > a factor 100 faster! How can I make the query perform good in the first > run too? > > Query and output from both first and second run of Explain Analyze is > pasted here: > > http://rafb.net/p/yrKyoA17.html > > ---------------------------(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 The query is faster the second run because the data pages were pulled into the buffer pool during the first run. I would suggest using the explain plan from the first run and test your changes on a recently started instance (or at least on an instance where enough activity has transpired to effectively rotate the buffer pages). /Kevin ---------------------------(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
