Re: Suboptimal evaluation of CASE expressions

On Tue, 11 Apr 2006, Tom Lane wrote:

> We could maybe change things so that the finalfunc isn't run unless the
> result value is actually demanded in the SELECT list or HAVING clause,
> but for 99.99% of applications checking that would be a waste of cycles,
> so I'm disinclined to do it.

I'm lacking experience here so I perfectly trust you that keeping
the default case as it is.  The question is, whether adding an
option to change the default might make sense.

> As Martijn said, really you want to fix
> the finalfunc so that it behaves sanely in corner cases.  An aggregate
> that fails on zero rows needs work, period.

Fully ACK.  As I hopefully made clear I just used it as a sign /
proof, that something works differently than I would regard reasonable
(before I understand the problem with the aggregate).

Kind regards
          Andreas.

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