Re: plpgsql.consistent_into

On Jan12, 2014, at 06:51 , Marko Tiikkaja <marko(at)joh(dot)to> wrote:
> I would humbly like to submit for your consideration my proposal for alleviating pain caused by one of the most annoying footguns in PL/PgSQL: the behaviour of SELECT .. INTO when the query returns more than one row. Some of you might know that no exception is raised in this case (as opposed to INSERT/UPDATE/DELETE .. INTO, all of them yielding TOO_MANY_ROWS), which can hide subtle bugs in queries if during testing the query always returns only one row or the "correct" one happens to be picked up every time. Additionally, the row_count() after execution is always going to be either 0 or 1, so even if you want to explicitly guard against potentially broken queries, you can't do so!
>
> So I added the following compile-time option:
>
> set plpgsql.consistent_into to true;

I don't think a GUC is the best way to handle this. Handling
this via a per-function setting similar to #variable_conflict would
IMHO be better.So a function containing

#into_surplus_rows error

would complain whereas

#into_surplus_rows ignore_for_select

would leave the behaviour unchanged.

best regards,
Florian Pflug