Re: Should we add GUCs to allow partition pruning to be disabled?

Robert Haas wrote:

> In defense of constraint exclusion, let me note that constraint
> exclusion is not restricted to inheritance cases.  It could eliminate
> the need to scan a completely unpartitioned table if the WHERE clause
> can be refuted by CHECK constraints.  It could eliminate the need to
> scan some partitions of a partitioned table based on whatever
> additional CHECK constraints exist beyond the partitioning
> constraints.

This is a great point that hadn't occurred to me.  It means that we
should keep constraint exclusion on its own <sect2> rather than relegate
it to <sect3>, as my proposed patch does.  I think it's a good idea to
add this point there too.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
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