Doc: clarify the restrictions of AFTER triggers with transition tables.

Etsuro Fujita · Etsuro Fujita · commit b49cb0b8df5e · 2025-08-02T18:30:04.000+09:00
It was not very clear that the triggers are only allowed on plain tables (not foreign tables). Also, rephrase the documentation for better readability. Follow up to commit 9e6104c. Reported-by: Etsuro Fujita <etsuro.fujita@gmail.com> Author: Ashutosh Bapat <ashutosh.bapat.oss@gmail.com> Reviewed-by: Etsuro Fujita <etsuro.fujita@gmail.com> Discussion: https://postgr.es/m/CAPmGK16XBs9ptNr8Lk4f-tJZogf6y-Prz%3D8yhvJbb_4dpsc3mQ%40mail.gmail.com Backpatch-through: 13
diff --git a/doc/src/sgml/ref/create_trigger.sgml b/doc/src/sgml/ref/create_trigger.sgml
@@ -199,9 +199,11 @@ CREATE [ OR REPLACE ] [ CONSTRAINT ] TRIGGER <replaceable class="parameter">name
    of the rows inserted, deleted, or modified by the current SQL statement.
    This feature lets the trigger see a global view of what the statement did,
    not just one row at a time.  This option is only allowed for
-   an <literal>AFTER</literal> trigger that is not a constraint trigger; also, if
-   the trigger is an <literal>UPDATE</literal> trigger, it must not specify
-   a <replaceable class="parameter">column_name</replaceable> list.
+   an <literal>AFTER</literal> trigger on a plain table (not a foreign table).
+   The trigger should not be a constraint trigger.  Also, if the trigger is
+   an <literal>UPDATE</literal> trigger, it must not specify
+   a <replaceable class="parameter">column_name</replaceable> list when using
+   this option.
    <literal>OLD TABLE</literal> may only be specified once, and only for a trigger
    that can fire on <literal>UPDATE</literal> or <literal>DELETE</literal>; it creates a
    transition relation containing the <firstterm>before-images</firstterm> of all rows
