Re: dubious optimization of the function in SELECT INTO target list

> On 08 Oct 2015, at 19:54, Alvaro Herrera <alvherre(at)2ndquadrant(dot)com> wrote:
>
> Oleksii Kliukin wrote:
>
>> Thank you, now it’s clear. I have to say there is no guarantee that
>> the computation would be useless. Someone might be calling a function
>> that updates/deletes rows in the SELECT INTO block, being forced to
>> use SELECT INTO by inability of pl/pgSQL to just discard the result of
>> a normal SELECT. I know one can use a loop or call PERFORM, but in
>> some cases (a complex CTE computing the data for the function being
>> called at the end, which updates the tables with this data) actually
>> using SELECT INTO looks like the easiest path to achieve the desired
>> result.
>
> So this whole issue is just because it is not possible to use PERFORM
> alongside WITH?

The issue is in the SELECT INTO behaviour, but the root cause is exactly the lack of support for perform in CTEs in pl/pgSQL.

Kind regards,
--
Oleksii