Re: GSOC13 proposal - extend RETURNING syntax

On Thu, May 02, 2013 at 06:28:53PM +0200, Andres Freund wrote:

On 2013-05-02 12:23:19 -0400, Tom Lane wrote:

Marko Tiikkaja <marko@joh.to> writes:

What I'm more interested in is: how can we make this feature work in 
PL/PgSQL where OLD means something different?

That's a really good point: if you follow this approach then you're
creating fundamental conflicts for use of the feature in trigger
functions or rules, which will necessarily have conflicting uses of
those names.  Yeah, we could define scoping rules such that there's
an unambiguous interpretation, but then the user is just out of luck
if he wants to reference the other definition.  (This problem is
probably actually worse if you implement with reserved words rather
than aliases.)

I'm thinking it would be better to invent some other notation for access
to old-row values.

prior/after? Both are unreserved keywords atm and it seems far less
likely to have conflicts than new/old.

BEFORE/AFTER seems more logical to me.  Yes, those words both have
meaning in, for example, a trigger definition, but they're clearly
separable by context.

Yay, bike-shedding!

Cheers,
David.

I prefer 'PRIOR & 'AFTER' as the both have the same length
- but perhaps that is just me!  :-)


Cheers,
Gavin