Re: Planner matching constants across tables in a join - Mailing list pgsql-performance

From Tom Lane
Subject Re: Planner matching constants across tables in a join
Date
Msg-id 19225.1046876918@sss.pgh.pa.us
Whole thread Raw
In response to Re: Planner matching constants across tables in a join  (Greg Stark <gsstark@mit.edu>)
List pgsql-performance
Greg Stark <gsstark@mit.edu> writes:
> Richard Huxton <dev@archonet.com> writes:
>> If I join two tables with a comparison to a constant on one, why can't the
>> planner see that the comparison applies to both tables:

> It sure does. Postgres does an impressive job of tracing equality clauses
> around for just this purpose.

CVS tip does.  Existing releases don't...

            regards, tom lane

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