Re: Strict Set Returning Functions

On Thu, Jun 16, 2011 at 12:24 AM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
>> On Wed, Jun 15, 2011 at 8:05 PM, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
>>> Simon Riggs <simon(at)2ndQuadrant(dot)com> writes:
>>>> So a function that is both STRICT and SET RETURNING will return rows.
>
>>> Really?  The case behaves as expected for me.
>
>> Seems that's the wrong question. Let me return to why I raised this:
>
>> Why does evaluate_function() specifically avoid returning NULL for a
>> set returning function?
>
> Because replacing the SRF call with a constant NULL would produce the
> wrong result, ie, a single row containing NULL, not zero rows.

OK, thanks.

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