Re: a very big table - Mailing list pgsql-sql

From Tom Lane
Subject Re: a very big table
Date
Msg-id 13636.1112575812@sss.pgh.pa.us
Whole thread Raw
In response to Re: a very big table  (PFC <lists@boutiquenumerique.com>)
List pgsql-sql
PFC <lists@boutiquenumerique.com> writes:
>     Here you don't need to LEFT JOIN, you can use a straight simple  
> unconstrained join because the rows generated by the LEFT JOINs which have  
> NULL in the right columns will be rejected by the WHERE clause anyway :

In recent versions of Postgres, the planner knows this and can make the
simplification for itself, at least if the operator or function used in
WHERE is properly marked as strict.
        regards, tom lane


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