Re: Statement level triggers

Vincenzo Romano wrote:
> Hi all.
>
> What'd be the behavior of a (plpgsql) trigger function when called as
> a statement level trigger?
> Let's say that a statement will involve more than one row.
> The documentation (v8.4.2, "35.1. Overview of Trigger Behavior") says:
>
> "Statement-level triggers do not currently have any way to examine the
> individual row(s) modified by the statement."

It means you don't have NEW or OLD record-variables. You can still
perform any queries you need to on the table affected and any other
tables of interest.

I find statement-level triggers to be useful mostly for sanity-checking.
I'll have an AFTER statement level trigger verify a certain invariant on
a table - like a table-level CHECK (as opposed to row-level CHECK).

--
Craig Ringer