Hello all. I've a performance problem on specific requests : When I use timestamps + interval in where clauses, query performance is slowed down by a factor of 20 or 30!!!! For exemple : select timestamp,value from measure where timestamp<now() and timestamp>(now() - '1 hour'::interval)
is 20 to 30 times longer than select timestamp,value from measure where timestamp<'2002-04-10 10:00' and timestamp>='2002-04-10 9:00'; So where is the bottleneck? A paradigm seems that now() and (now() - '1hour'::interval) is evaluated for each row comparison... Am I right? Thus is there a way to make SQL interpreter evaluate this by rewriting them before launching any comparisons? Or do I have to rewrite all my application queries and calculate each time now() and interval predicates? Thanks by advance -- Jean-Christophe ARNU s/w developer Paratronic France > Notre devoir, pour leur bien et pour le bien de Linux, est de te > flinguer avant que tu ne les sacrifies (fût-ce avec les meilleures > intentions du monde). -+- TP In: Guide du linuxien pervers : "De la pédagogie par l'Exemple" ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/users-lounge/docs/faq.html