Allow event trigger table_rewrite for ALTER MATERIALIZED VIEW

This event can happen when using SET ACCESS METHOD, as the data files of
the materialized need a full refresh but this command tag was not
updated to reflect that.  The documentation is updated to track this
behavior.

Author: Onder Kalaci
Discussion: https://postgr.es/m/CACawEhXwHN3X34FiwoYG8vXR-oyUdrp7qcfRWSzS+NPahS5gSw@mail.gmail.com
Backpatch-through: 15

doc/src/sgml/event-trigger.sgml

@@ -242,7 +242,7 @@
         <entry align="center"><literal>X</literal></entry>
         <entry align="center"><literal>X</literal></entry>
         <entry align="center"><literal>-</literal></entry>
-        <entry align="center"><literal>-</literal></entry>
+        <entry align="center"><literal>X</literal></entry>
         <entry align="left"></entry>
        </row>
        <row>

src/include/tcop/cmdtaglist.h

@@ -42,7 +42,7 @@ PG_CMDTAG(CMDTAG_ALTER_FUNCTION, "ALTER FUNCTION", true, false, false)
 PG_CMDTAG(CMDTAG_ALTER_INDEX, "ALTER INDEX", true, false, false)
 PG_CMDTAG(CMDTAG_ALTER_LANGUAGE, "ALTER LANGUAGE", true, false, false)
 PG_CMDTAG(CMDTAG_ALTER_LARGE_OBJECT, "ALTER LARGE OBJECT", true, false, false)
-PG_CMDTAG(CMDTAG_ALTER_MATERIALIZED_VIEW, "ALTER MATERIALIZED VIEW", true, false, false)
+PG_CMDTAG(CMDTAG_ALTER_MATERIALIZED_VIEW, "ALTER MATERIALIZED VIEW", true, true, false)
 PG_CMDTAG(CMDTAG_ALTER_OPERATOR, "ALTER OPERATOR", true, false, false)
 PG_CMDTAG(CMDTAG_ALTER_OPERATOR_CLASS, "ALTER OPERATOR CLASS", true, false, false)
 PG_CMDTAG(CMDTAG_ALTER_OPERATOR_FAMILY, "ALTER OPERATOR FAMILY", true, false, false)

src/test/regress/expected/event_trigger.out

@@ -516,6 +516,11 @@ alter table rewriteme
  add column another int default -1,
  alter column foo type numeric(10,4);
 NOTICE:  Table 'rewriteme' is being rewritten (reason = 4)
+-- matview rewrite when changing access method
+CREATE MATERIALIZED VIEW heapmv USING heap AS SELECT 1 AS a;
+ALTER MATERIALIZED VIEW heapmv SET ACCESS METHOD heap2;
+NOTICE:  Table 'heapmv' is being rewritten (reason = 8)
+DROP MATERIALIZED VIEW heapmv;
 -- shouldn't trigger a table_rewrite event
 alter table rewriteme alter column foo type numeric(12,4);
 begin;

src/test/regress/sql/event_trigger.sql

@@ -379,6 +379,11 @@ alter table rewriteme
  add column another int default -1,
  alter column foo type numeric(10,4);
 
+-- matview rewrite when changing access method
+CREATE MATERIALIZED VIEW heapmv USING heap AS SELECT 1 AS a;
+ALTER MATERIALIZED VIEW heapmv SET ACCESS METHOD heap2;
+DROP MATERIALIZED VIEW heapmv;
+
 -- shouldn't trigger a table_rewrite event
 alter table rewriteme alter column foo type numeric(12,4);
 begin;