On Tue, Jun 16, 2020 at 01:39:45PM -0400, Tom Lane wrote:
> Bruce Momjian <br...@momjian.us> writes:
> > I have developed the attached patch which is in a better direction.
>
> I still wish you wouldn't jam this topic into an only-marginally-related
> sentence. In the case at hand, the point that the existing text is
> making is that a no-op update will fire triggers. Which is not
> something that suppress_redundant_updates_trigger will suppress,
> so again it seems confusing to mention that in the same breath.
>
> I think that perhaps the right thing to do is add a new para to
> CREATE TRIGGER's "Notes" section, along the lines of
>
> There are a few built-in trigger functions that can be used
> to solve common problems without having to write your own trigger
> code. See Section 9.28.
>
> This would have the advantage of covering the other built-in triggers
> not only suppress_redundant_updates_trigger.
OK, I didn't think there was enough desire to put it its own paragraph,
but I like the idea of mentioning all of the trigger functions; patch
attached.
--
Bruce Momjian <br...@momjian.us> https://momjian.us
EnterpriseDB https://enterprisedb.com
The usefulness of a cup is in its emptiness, Bruce Lee
diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml
index 303881fcfb..289dd1d9da 100644
--- a/doc/src/sgml/ref/create_trigger.sgml
+++ b/doc/src/sgml/ref/create_trigger.sgml
@@ -457,6 +457,12 @@ UPDATE OF <replaceable>column_name1</replaceable> [, <replaceable>column_name2</
value did not change.
</para>
+ <para>
+ There are a few built-in trigger functions that can be used to
+ solve common problems without having to write your own trigger code;
+ see <xref linkend="functions-trigger"/>.
+ </para>
+
<para>
In a <literal>BEFORE</literal> trigger, the <literal>WHEN</literal> condition is
evaluated just before the function is or would be executed, so using
