Re: [PERFORM] typoed column name, but postgres didn't grump

On Tue, Nov 2, 2010 at 4:34 PM, Kevin Grittner
<Kevin(dot)Grittner(at)wicourts(dot)gov> wrote:
> Jon Nelson <jnelson+pgsql(at)jamponi(dot)net> wrote:
>
>> If I saw this behavior ( a.b also meaning b(a) ) in another SQL
>> engine, I would consider it a thoroughly unintuitive wart
>
> I think the main reason it has been kept is the converse -- if you
> define a function "b" which takes record "a" as its only parameter,
> you have effectively created a "generated column" on any relation
> using record type "a".  Kind of.  It won't show up in the display of
> the relation's structure or in a SELECT *, and you can't use it in
> an unqualified reference; but you can use a.b to reference it, which
> can be convenient.

Aha. I think I understand, now. I also read up on CAST behavior
changes between 8.1 and 8.4 (what I'm using), and I found section
34.4.2 "SQL Functions on Composite Types" quite useful.

Thanks!

--
Jon