diff --git a/doc/src/sgml/ref/merge.sgml b/doc/src/sgml/ref/merge.sgml
index ecbcd8345d874..c2e181066a4e1 100644
--- a/doc/src/sgml/ref/merge.sgml
+++ b/doc/src/sgml/ref/merge.sgml
@@ -23,37 +23,37 @@ PostgreSQL documentation
[ WITH with_query [, ...] ]
MERGE INTO [ ONLY ] target_table_name [ * ] [ [ AS ] target_alias ]
-USING data_source ON join_condition
-when_clause [...]
-[ RETURNING [ WITH ( { OLD | NEW } AS output_alias [, ...] ) ]
- { * | output_expression [ [ AS ] output_name ] } [, ...] ]
+ USING data_source ON join_condition
+ when_clause [...]
+ [ RETURNING [ WITH ( { OLD | NEW } AS output_alias [, ...] ) ]
+ { * | output_expression [ [ AS ] output_name ] } [, ...] ]
where data_source is:
-{ [ ONLY ] source_table_name [ * ] | ( source_query ) } [ [ AS ] source_alias ]
+ { [ ONLY ] source_table_name [ * ] | ( source_query ) } [ [ AS ] source_alias ]
and when_clause is:
-{ WHEN MATCHED [ AND condition ] THEN { merge_update | merge_delete | DO NOTHING } |
- WHEN NOT MATCHED BY SOURCE [ AND condition ] THEN { merge_update | merge_delete | DO NOTHING } |
- WHEN NOT MATCHED [ BY TARGET ] [ AND condition ] THEN { merge_insert | DO NOTHING } }
+ { WHEN MATCHED [ AND condition ] THEN { merge_update | merge_delete | DO NOTHING } |
+ WHEN NOT MATCHED BY SOURCE [ AND condition ] THEN { merge_update | merge_delete | DO NOTHING } |
+ WHEN NOT MATCHED [ BY TARGET ] [ AND condition ] THEN { merge_insert | DO NOTHING } }
and merge_insert is:
-INSERT [( column_name [, ...] )]
-[ OVERRIDING { SYSTEM | USER } VALUE ]
-{ VALUES ( { expression | DEFAULT } [, ...] ) | DEFAULT VALUES }
+ INSERT [( column_name [, ...] )]
+ [ OVERRIDING { SYSTEM | USER } VALUE ]
+ { VALUES ( { expression | DEFAULT } [, ...] ) | DEFAULT VALUES }
and merge_update is:
-UPDATE SET { column_name = { expression | DEFAULT } |
- ( column_name [, ...] ) = [ ROW ] ( { expression | DEFAULT } [, ...] ) |
- ( column_name [, ...] ) = ( sub-SELECT )
- } [, ...]
+ UPDATE SET { column_name = { expression | DEFAULT } |
+ ( column_name [, ...] ) = [ ROW ] ( { expression | DEFAULT } [, ...] ) |
+ ( column_name [, ...] ) = ( sub-SELECT )
+ } [, ...]
and merge_delete is:
-DELETE
+ DELETE
@@ -106,10 +106,11 @@ DELETE
to compute and return value(s) based on each row inserted, updated, or
deleted. Any expression using the source or target table's columns, or
the merge_action()
- function can be computed. When an INSERT or
+ function can be computed. By default, when an INSERT or
UPDATE action is performed, the new values of the target
- table's columns are used. When a DELETE is performed,
- the old values of the target table's columns are used. The syntax of the
+ table's columns are used, and when a DELETE is performed,
+ the old values of the target table's columns are used, but it is also
+ possible to explicitly request old and new values. The syntax of the
RETURNING list is identical to that of the output list
of SELECT.
diff --git a/doc/src/sgml/ref/update.sgml b/doc/src/sgml/ref/update.sgml
index 12ec5ba070939..40cca06394636 100644
--- a/doc/src/sgml/ref/update.sgml
+++ b/doc/src/sgml/ref/update.sgml
@@ -57,7 +57,8 @@ UPDATE [ ONLY ] table_name [ * ] [
to compute and return value(s) based on each row actually updated.
Any expression using the table's columns, and/or columns of other
tables mentioned in FROM, can be computed.
- The new (post-update) values of the table's columns are used.
+ By default, the new (post-update) values of the table's columns are used,
+ but it is also possible to request the old (pre-update) values.
The syntax of the RETURNING list is identical to that of the
output list of SELECT.