Re: delta relations in AFTER triggers

On Wed, Sep 3, 2014 at 10:49 PM, Kevin Grittner <kgrittn@ymail.com> wrote:
> Marti Raudsepp <marti@juffo.org> wrote:
>> The concept of "lightweight relations" that pop into existence when a
>> certain kind of trigger definition is used somewhere in the function
>> stack, without a CREATE TABLE, without being discoverable in
>> information_schema etc., I find needs some more justification than
>> I've seen in this thread. So far I've only heard that it's more
>> convenient to implement in the current PostgreSQL code base.
>
> It is required by the SQL standard.

I had a cursory read of the SQL 20nn draft and I don't get this
impression. The only place I could find discussing the behavior of
"transition tables" is in Foundation "4.39.1 General description of
triggers", which says:

"Special variables make the data in the transition table(s) available
to the triggered action. For a statement-level
trigger the variable is one whose value is a transition table."

There is no information about the scoping of such variables, so I
assume it refers to a regular locally scoped variable.

Did I miss something? Are you reading a different version of the spec?

Regards,
Marti