Re: Rewritten queries

 --- Tom Lane <tgl@sss.pgh.pa.us> escribió:
> Jaime Casanova <systemguards@yahoo.com> writes:
> > What version of postgres are u using?
> > I don't see that particular behavior in coalesce.
>
> > someone knows if this is the behavior in any older
> > version of pg?
>
> Yes.  Since about 7.4 COALESCE is a first-class
> expression node type,
> but before that the parser expanded it into a CASE
> construct.
>
> The CASE implementation is lacking in that it may
> evaluate the arguments
> more than once, which could be wrong if they are
> volatile values.
>
>             regards, tom lane
>

So, i think the recommended suggestion will be to
upgrade to a newer version. Maybe you want to wait
until 8 is out.

regards,
Jaime Casanova

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