While testing MERGE, I noticed that it supports inheritance
hierarchies and the ONLY keyword, but that isn't documented. Attached
is a patch to merge.sgml, borrowing text from update.sgml and
delete.sgml.
I note that there are also a couple of places early in the manual
(advanced.sgml and ddl.sgml) that also discuss inheritance, citing
SELECT, UPDATE and DELETE as examples of (already-discussed) commands
that support ONLY. However, since MERGE isn't mentioned until much
later in the manual, it's probably best to leave those as-is. They
don't claim to be complete lists of commands supporting ONLY, and it
would be a pain to make them that.
Regards,
Dean
diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
new file mode 100644
index e07adda..bc7f4b4
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -22,13 +22,13 @@ PostgreSQL documentation
<refsynopsisdiv>
<synopsis>
[ WITH <replaceable class="parameter">with_query</replaceable> [, ...] ]
-MERGE INTO <replaceable class="parameter">target_table_name</replaceable> [ [ AS ] <replaceable class="parameter">target_alias</replaceable> ]
+MERGE INTO [ ONLY ] <replaceable class="parameter">target_table_name</replaceable> [ [ AS ] <replaceable class="parameter">target_alias</replaceable> ]
USING <replaceable class="parameter">data_source</replaceable> ON <replaceable class="parameter">join_condition</replaceable>
<replaceable class="parameter">when_clause</replaceable> [...]
<phrase>where <replaceable class="parameter">data_source</replaceable> is:</phrase>
-{ <replaceable class="parameter">source_table_name</replaceable> | ( <replaceable class="parameter">source_query</replaceable> ) } [ [ AS ] <replaceable class="parameter">source_alias</replaceable> ]
+{ [ ONLY ] <replaceable class="parameter">source_table_name</replaceable> | ( <replaceable class="parameter">source_query</replaceable> ) } [ [ AS ] <replaceable class="parameter">source_alias</replaceable> ]
<phrase>and <replaceable class="parameter">when_clause</replaceable> is:</phrase>
@@ -129,6 +129,14 @@ DELETE
<listitem>
<para>
The name (optionally schema-qualified) of the target table to merge into.
+ If <literal>ONLY</literal> is specified before the table name, matching
+ rows are updated or deleted in the named table only. If
+ <literal>ONLY</literal> is not specified, matching rows are also updated
+ or deleted in any tables inheriting from the named table. Optionally,
+ <literal>*</literal> can be specified after the table name to explicitly
+ indicate that descendant tables are included. The
+ <literal>ONLY</literal> keyword and <literal>*</literal> option do not
+ affect insert actions, which always insert into the named table only.
</para>
</listitem>
</varlistentry>
@@ -151,7 +159,12 @@ DELETE
<listitem>
<para>
The name (optionally schema-qualified) of the source table, view, or
- transition table.
+ transition table. If <literal>ONLY</literal> is specified before the
+ table name, matching rows are included from the named table only. If
+ <literal>ONLY</literal> is not specified, matching rows are also included
+ from any tables inheriting from the named table. Optionally,
+ <literal>*</literal> can be specified after the table name to explicitly
+ indicate that descendant tables are included.
</para>
</listitem>
</varlistentry>
