Re: Q: optimizer does the wrong thing on join

Patrick Preuss wrote: > > Hi, > > we have a join with several tables, written with the most restricting table > stands at the top (the right thing, I guess). > What does the optimizer do? He just flips the order, and scans the biggest > table first, sequentially!!! Is this a problem for Update Statistics? > > Thanks, > Patrick > > -- > Patrick Preuss :- on this side of the video screen > ppr@deckard.hb.north.de :- on the other side > "A just machine to make big decisions / Programmed by fellows with compassion > and vision / We'll be free when their work is done / We'll be eternally free > yes and eternally young." D.Fagen I've found this problem in DB2 as well. To get around it we reduced the number of constraints on that 'most restricted table' to only the minimum number necessary. Completely backwards to any SQL theory that I've had but since when is theory actually practiced.