Re: why can't plpgsql return a row-expression?

Asif Rehman escribió:
> Hi,
>
> I have tried to solve this issue. Please see the attached patch.
>
> With this patch, any expression is allowed in the return statement. For any
> invalid expression an error is generated without doing any special handling.
> When a row expression is used in the return statement then the resultant
> tuple will have rowtype in a single column that needed to be extracted.
> Hence I have handled that case in exec_stmt_return().
>
> any comments/suggestions?

Hmm. We're running an I/O cast during do_tup_convert() now, and look
up the required functions for each tuple. I think if we're going to
support this operation at that level, we need to look up the necessary
functions at convert_tuples_by_foo level, and then apply unconditionally
if they've been set up.

Also, what are the implicancies for existing users of tupconvert? Do we
want to apply casting during ANALYZE for example? AFAICS the patch
shouldn't break any case that works today, but I don't see that there
has been any analysis of this.

(I looked at the patch posted in the thread started by Pavel elsewhere.
I'm replying to both emails in the interest of keeping things properly
linked.)

--
Álvaro Herrera http://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Training & Services