Re: Proposal: plpgsql - "for in array" statement

Pavel Stehule <pavel(dot)stehule(at)gmail(dot)com> writes:
> 2010/9/28 Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>:
>> As an example, is this a for-in-query or a
>> for-in-array?
>>
>> FOR v IN (SELECT arraycol FROM tab) LOOP ...

> This is a subquery - so it is a for-in-array - should return one row
> with one column.

That's not obvious at all. It's legal right now to write that, and it
will be interpreted as for-in-query. Furthermore, there are cases where
it's essential to be able to write a left paren before SELECT, so that
you can control the precedence of UNION/INTERSECT/EXCEPT constructs.
So you're proposing to remove functionality and break existing code in
order to have a "simple" syntax for for-in-array.

regards, tom lane