Optimizer problems - Mailing list pgsql-hackers

From Bruce Momjian
Subject Optimizer problems
Date
Msg-id 199902081823.NAA16833@candle.pha.pa.us
Whole thread Raw
Responses Re: [HACKERS] Optimizer problems  (jwieck@debis.com (Jan Wieck))
List pgsql-hackers
I am fixing p_ordering(now called path_order) to properly display in
outNode/readNode and friends.

This structure is never output during debug runs.  Without the display,
it is hard to see if the optimizer is doing what it should.

My suspicion is that RelOptInfo is retaining many duplicate pathlist
Path's that have duplicate/useless PathOrder/key combinations, causing
optimization of large queries to be very slow.

I'll keep going.

Is it me, or have things gotten very busy in the last week on the
hackers list, with tons of new features coming in?

--  Bruce Momjian                        |  http://www.op.net/~candle maillist@candle.pha.pa.us            |  (610)
853-3000+  If your life is a hard drive,     |  830 Blythe Avenue +  Christ can be your backup.        |  Drexel Hill,
Pennsylvania19026
 


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