Improve docs on updatable views
Introduce the options before going into details, and add a link to the
CREATE TRIGGER documentation.
Author: David Johnston
Discussion:
@@ -797,6 +797,10 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 WHERE t1.a = t2.a;
relation points at a subquery range-table entry, which will not
work. There are several ways in which <productname>PostgreSQL</productname>
can support the appearance of updating a view, however.
+ In order of user-experienced complexity those are: automatically substitute
+ in the underlying table for the view, execute a user-defined trigger,
+ or rewrite the query per a user-defined rule.
+ These options are discussed below.
</para>
<para>
@@ -812,7 +816,8 @@ SELECT t1.a, t2.b, t1.ctid FROM t1, t2 WHERE t1.a = t2.a;
<para>
Alternatively, the operation may be handled by a user-provided
- <literal>INSTEAD OF</literal> trigger on the view.
+ <literal>INSTEAD OF</literal> trigger on the view
+ (see <xref linkend="sql-createtrigger"/>).
Rewriting works slightly differently
in this case. For <command>INSERT</command>, the rewriter does
nothing at all with the view, leaving it as the result relation
