From: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
---|---|
To: | "David G(dot) Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> |
Cc: | Thomas Güttler <guettliml(at)thomas-guettler(dot)de>, "pgsql-general(at)postgresql(dot)org" <pgsql-general(at)postgresql(dot)org> |
Subject: | Re: Do docs miss information about timing of triggers? |
Date: | 2016-05-26 13:43:54 |
Message-ID: | 25868.1464270234@sss.pgh.pa.us |
Views: | Raw Message | Whole Thread | Download mbox | Resend email |
Thread: | |
Lists: | pgsql-general |
"David G. Johnston" <david(dot)g(dot)johnston(at)gmail(dot)com> writes:
> On Thu, May 26, 2016 at 8:50 AM, Thomas Gttler <
> guettliml(at)thomas-guettler(dot)de> wrote:
>> OK, timing of constraint triggers is explained.
>> But I think the docs don't state the timing of normal AFTER triggers.
> Through omission.
It's not *that* bad. See
https://www.postgresql.org/docs/9.5/static/trigger-definition.html
Triggers are also classified according to whether they fire before,
after, or instead of the operation. These are referred to as BEFORE
triggers, AFTER triggers, and INSTEAD OF triggers
respectively. Statement-level BEFORE triggers naturally fire before
the statement starts to do anything, while statement-level AFTER
triggers fire at the very end of the statement. These types of
triggers may be defined on tables or views. Row-level BEFORE triggers
fire immediately before a particular row is operated on, while
row-level AFTER triggers fire at the end of the statement (but before
any statement-level AFTER triggers). ...
regards, tom lane
From | Date | Subject | |
---|---|---|---|
Next Message | Adrian Klaver | 2016-05-26 13:50:04 | Re: Do docs miss information about timing of triggers? |
Previous Message | David G. Johnston | 2016-05-26 13:15:27 | Re: Do docs miss information about timing of triggers? |