Strict Set Returning Functions

STRICT functions return NULL if any of their inputs are NULL according
to the manual, so that they need not be executed at all.

Unless it is a Set Returning Function, in which case a NULL input is
not reduced nor does it to appear to be handled as a special case in
the executor function scan code.

So a function that is both STRICT and SET RETURNING will return rows.

Presumably this is just a case of missing documentation?

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 Simon Riggs                   http://www.2ndQuadrant.com/
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