Re: The order of fields around the "=" in the WHERE conditions - Mailing list pgsql-performance

From Tom Lane
Subject Re: The order of fields around the "=" in the WHERE conditions
Date
Msg-id 17162.1144101482@sss.pgh.pa.us
Whole thread Raw
In response to The order of fields around the "=" in the WHERE conditions  ("Mike Quinn" <mquinn@co.merced.ca.us>)
Responses Re: The order of fields around the "=" in the WHERE  ("Mike Quinn" <mquinn@co.merced.ca.us>)
List pgsql-performance
"Mike Quinn" <mquinn@co.merced.ca.us> writes:
> -- The order of fields around the "=" in the WHERE conditions
> -- affects the query plan.

BTW, what's the datatype(s) of the join columns?  The behavior looks
consistent with the idea that the planner doesn't think it can commute
the join conditions, which would be a bug/omission in the set of
operators existing for the datatype(s).  I believe we've got commutators
for all the standard '=' operators, but a contrib or third-party
datatype might be missing this.

            regards, tom lane

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