INSERT INTO ft2 (c1,c2,c3) SELECT c1+1000,c2+100, c3 || c3 FROM ft2 LIMIT 20;
INSERT INTO ft2 (c1,c2,c3)
- VALUES (1101,201,'aaa'), (1102,202,'bbb'), (1103,203,'ccc') RETURNING *;
- c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
-------+-----+-----+----+----+----+------------+----
- 1101 | 201 | aaa | | | | ft2 |
- 1102 | 202 | bbb | | | | ft2 |
- 1103 | 203 | ccc | | | | ft2 |
+ VALUES (1101,201,'aaa'), (1102,202,'bbb'), (1103,203,'ccc') RETURNING old, new, old.*, new.*;
+ old | new | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+-----+---------------------------------+----+----+----+----+----+----+----+----+------+-----+-----+----+----+----+------------+----
+ | (1101,201,aaa,,,,"ft2 ",) | | | | | | | | | 1101 | 201 | aaa | | | | ft2 |
+ | (1102,202,bbb,,,,"ft2 ",) | | | | | | | | | 1102 | 202 | bbb | | | | ft2 |
+ | (1103,203,ccc,,,,"ft2 ",) | | | | | | | | | 1103 | 203 | ccc | | | | ft2 |
(3 rows)
INSERT INTO ft2 (c1,c2,c3) VALUES (1104,204,'ddd'), (1105,205,'eee');
1017 | 507 | 0001700017_update7 | | | | ft2 |
(102 rows)
+BEGIN;
+ EXPLAIN (verbose, costs off)
+ UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7b' WHERE c1 % 10 = 7 AND c1 < 40
+ RETURNING old.*, new.*; -- can't be pushed down
+ QUERY PLAN
+----------------------------------------------------------------------------------------------------------------------------------------------
+ Update on public.ft2
+ Output: old.c1, old.c2, old.c3, old.c4, old.c5, old.c6, old.c7, old.c8, new.c1, new.c2, new.c3, new.c4, new.c5, new.c6, new.c7, new.c8
+ Remote SQL: UPDATE "S 1"."T 1" SET c2 = $2, c3 = $3 WHERE ctid = $1 RETURNING "C 1", c2, c3, c4, c5, c6, c7, c8
+ -> Foreign Scan on public.ft2
+ Output: (c2 + 400), (c3 || '_update7b'::text), ctid, ft2.*
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8, ctid FROM "S 1"."T 1" WHERE (("C 1" < 40)) AND ((("C 1" % 10) = 7)) FOR UPDATE
+(6 rows)
+
+ UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7b' WHERE c1 % 10 = 7 AND c1 < 40
+ RETURNING old.*, new.*;
+ c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8
+----+-----+---------------+------------------------------+--------------------------+----+------------+-----+----+-----+------------------------+------------------------------+--------------------------+----+------------+-----
+ 7 | 407 | 00007_update7 | Thu Jan 08 00:00:00 1970 PST | Thu Jan 08 00:00:00 1970 | 7 | 7 | foo | 7 | 807 | 00007_update7_update7b | Thu Jan 08 00:00:00 1970 PST | Thu Jan 08 00:00:00 1970 | 7 | 7 | foo
+ 17 | 407 | 00017_update7 | Sun Jan 18 00:00:00 1970 PST | Sun Jan 18 00:00:00 1970 | 7 | 7 | foo | 17 | 807 | 00017_update7_update7b | Sun Jan 18 00:00:00 1970 PST | Sun Jan 18 00:00:00 1970 | 7 | 7 | foo
+ 27 | 407 | 00027_update7 | Wed Jan 28 00:00:00 1970 PST | Wed Jan 28 00:00:00 1970 | 7 | 7 | foo | 27 | 807 | 00027_update7_update7b | Wed Jan 28 00:00:00 1970 PST | Wed Jan 28 00:00:00 1970 | 7 | 7 | foo
+ 37 | 407 | 00037_update7 | Sat Feb 07 00:00:00 1970 PST | Sat Feb 07 00:00:00 1970 | 7 | 7 | foo | 37 | 807 | 00037_update7_update7b | Sat Feb 07 00:00:00 1970 PST | Sat Feb 07 00:00:00 1970 | 7 | 7 | foo
+(4 rows)
+
+ROLLBACK;
EXPLAIN (verbose, costs off)
UPDATE ft2 SET c2 = ft2.c2 + 500, c3 = ft2.c3 || '_update9', c7 = DEFAULT
FROM ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 9; -- can be pushed down
1105 |
(103 rows)
+BEGIN;
+ EXPLAIN (verbose, costs off)
+ DELETE FROM ft2 WHERE c1 % 10 = 6 AND c1 < 40 RETURNING old.c1, c4; -- can't be pushed down
+ QUERY PLAN
+-----------------------------------------------------------------------------------------------------------
+ Delete on public.ft2
+ Output: old.c1, c4
+ Remote SQL: DELETE FROM "S 1"."T 1" WHERE ctid = $1 RETURNING "C 1", c4
+ -> Foreign Scan on public.ft2
+ Output: ctid
+ Remote SQL: SELECT ctid FROM "S 1"."T 1" WHERE (("C 1" < 40)) AND ((("C 1" % 10) = 6)) FOR UPDATE
+(6 rows)
+
+ DELETE FROM ft2 WHERE c1 % 10 = 6 AND c1 < 40 RETURNING old.c1, c4;
+ c1 | c4
+----+------------------------------
+ 6 | Wed Jan 07 00:00:00 1970 PST
+ 16 | Sat Jan 17 00:00:00 1970 PST
+ 26 | Tue Jan 27 00:00:00 1970 PST
+ 36 | Fri Feb 06 00:00:00 1970 PST
+(4 rows)
+
+ROLLBACK;
EXPLAIN (verbose, costs off)
DELETE FROM ft2 USING ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 2; -- can be pushed down
QUERY PLAN
(1296,96,foo,,,,"ft2 ",) | 1296 | 96 | foo | | | | ft2 | | (96,97,AAA096) | 96 | 97 | AAA096
(16 rows)
+BEGIN;
+ EXPLAIN (verbose, costs off)
+ UPDATE ft2 SET c3 = 'bar'
+ FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
+ WHERE ft2.c1 > 1200 AND ft2.c2 = ft4.c1
+ RETURNING old, new, ft2, ft2.*, ft4, ft4.*; -- can't be pushed down
+ QUERY PLAN
+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
+ Update on public.ft2
+ Output: old.*, new.*, ft2.*, ft2.c1, ft2.c2, ft2.c3, ft2.c4, ft2.c5, ft2.c6, ft2.c7, ft2.c8, ft4.*, ft4.c1, ft4.c2, ft4.c3
+ Remote SQL: UPDATE "S 1"."T 1" SET c3 = $2 WHERE ctid = $1 RETURNING "C 1", c2, c3, c4, c5, c6, c7, c8
+ -> Foreign Scan
+ Output: 'bar'::text, ft2.ctid, ft2.*, ft4.*, ft5.*, ft4.c1, ft4.c2, ft4.c3
+ Relations: ((public.ft2) INNER JOIN (public.ft4)) INNER JOIN (public.ft5)
+ Remote SQL: SELECT r1.ctid, CASE WHEN (r1.*)::text IS NOT NULL THEN ROW(r1."C 1", r1.c2, r1.c3, r1.c4, r1.c5, r1.c6, r1.c7, r1.c8) END, CASE WHEN (r2.*)::text IS NOT NULL THEN ROW(r2.c1, r2.c2, r2.c3) END, CASE WHEN (r3.*)::text IS NOT NULL THEN ROW(r3.c1, r3.c2, r3.c3) END, r2.c1, r2.c2, r2.c3 FROM (("S 1"."T 1" r1 INNER JOIN "S 1"."T 3" r2 ON (((r1.c2 = r2.c1)) AND ((r1."C 1" > 1200)))) INNER JOIN "S 1"."T 4" r3 ON (((r2.c1 = r3.c1)))) FOR UPDATE OF r1
+ -> Nested Loop
+ Output: ft2.ctid, ft2.*, ft4.*, ft5.*, ft4.c1, ft4.c2, ft4.c3
+ Join Filter: (ft4.c1 = ft5.c1)
+ -> Sort
+ Output: ft2.ctid, ft2.*, ft2.c2, ft4.*, ft4.c1, ft4.c2, ft4.c3
+ Sort Key: ft2.c2
+ -> Hash Join
+ Output: ft2.ctid, ft2.*, ft2.c2, ft4.*, ft4.c1, ft4.c2, ft4.c3
+ Hash Cond: (ft2.c2 = ft4.c1)
+ -> Foreign Scan on public.ft2
+ Output: ft2.ctid, ft2.*, ft2.c2
+ Remote SQL: SELECT "C 1", c2, c3, c4, c5, c6, c7, c8, ctid FROM "S 1"."T 1" WHERE (("C 1" > 1200)) FOR UPDATE
+ -> Hash
+ Output: ft4.*, ft4.c1, ft4.c2, ft4.c3
+ -> Foreign Scan on public.ft4
+ Output: ft4.*, ft4.c1, ft4.c2, ft4.c3
+ Remote SQL: SELECT c1, c2, c3 FROM "S 1"."T 3"
+ -> Materialize
+ Output: ft5.*, ft5.c1
+ -> Foreign Scan on public.ft5
+ Output: ft5.*, ft5.c1
+ Remote SQL: SELECT c1, c2, c3 FROM "S 1"."T 4"
+(29 rows)
+
+ UPDATE ft2 SET c3 = 'bar'
+ FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
+ WHERE ft2.c1 > 1200 AND ft2.c2 = ft4.c1
+ RETURNING old, new, ft2, ft2.*, ft4, ft4.*;
+ old | new | ft2 | c1 | c2 | c3 | c4 | c5 | c6 | c7 | c8 | ft4 | c1 | c2 | c3
+--------------------------------+--------------------------------+--------------------------------+------+----+-----+----+----+----+------------+----+----------------+----+----+--------
+ (1206,6,foo,,,,"ft2 ",) | (1206,6,bar,,,,"ft2 ",) | (1206,6,bar,,,,"ft2 ",) | 1206 | 6 | bar | | | | ft2 | | (6,7,AAA006) | 6 | 7 | AAA006
+ (1212,12,foo,,,,"ft2 ",) | (1212,12,bar,,,,"ft2 ",) | (1212,12,bar,,,,"ft2 ",) | 1212 | 12 | bar | | | | ft2 | | (12,13,AAA012) | 12 | 13 | AAA012
+ (1224,24,foo,,,,"ft2 ",) | (1224,24,bar,,,,"ft2 ",) | (1224,24,bar,,,,"ft2 ",) | 1224 | 24 | bar | | | | ft2 | | (24,25,AAA024) | 24 | 25 | AAA024
+ (1230,30,foo,,,,"ft2 ",) | (1230,30,bar,,,,"ft2 ",) | (1230,30,bar,,,,"ft2 ",) | 1230 | 30 | bar | | | | ft2 | | (30,31,AAA030) | 30 | 31 | AAA030
+ (1242,42,foo,,,,"ft2 ",) | (1242,42,bar,,,,"ft2 ",) | (1242,42,bar,,,,"ft2 ",) | 1242 | 42 | bar | | | | ft2 | | (42,43,AAA042) | 42 | 43 | AAA042
+ (1248,48,foo,,,,"ft2 ",) | (1248,48,bar,,,,"ft2 ",) | (1248,48,bar,,,,"ft2 ",) | 1248 | 48 | bar | | | | ft2 | | (48,49,AAA048) | 48 | 49 | AAA048
+ (1260,60,foo,,,,"ft2 ",) | (1260,60,bar,,,,"ft2 ",) | (1260,60,bar,,,,"ft2 ",) | 1260 | 60 | bar | | | | ft2 | | (60,61,AAA060) | 60 | 61 | AAA060
+ (1266,66,foo,,,,"ft2 ",) | (1266,66,bar,,,,"ft2 ",) | (1266,66,bar,,,,"ft2 ",) | 1266 | 66 | bar | | | | ft2 | | (66,67,AAA066) | 66 | 67 | AAA066
+ (1278,78,foo,,,,"ft2 ",) | (1278,78,bar,,,,"ft2 ",) | (1278,78,bar,,,,"ft2 ",) | 1278 | 78 | bar | | | | ft2 | | (78,79,AAA078) | 78 | 79 | AAA078
+ (1284,84,foo,,,,"ft2 ",) | (1284,84,bar,,,,"ft2 ",) | (1284,84,bar,,,,"ft2 ",) | 1284 | 84 | bar | | | | ft2 | | (84,85,AAA084) | 84 | 85 | AAA084
+ (1296,96,foo,,,,"ft2 ",) | (1296,96,bar,,,,"ft2 ",) | (1296,96,bar,,,,"ft2 ",) | 1296 | 96 | bar | | | | ft2 | | (96,97,AAA096) | 96 | 97 | AAA096
+ (1218,18,foo,,,,"ft2 ",) | (1218,18,bar,,,,"ft2 ",) | (1218,18,bar,,,,"ft2 ",) | 1218 | 18 | bar | | | | ft2 | | (18,19,AAA018) | 18 | 19 | AAA018
+ (1236,36,foo,,,,"ft2 ",) | (1236,36,bar,,,,"ft2 ",) | (1236,36,bar,,,,"ft2 ",) | 1236 | 36 | bar | | | | ft2 | | (36,37,AAA036) | 36 | 37 | AAA036
+ (1254,54,foo,,,,"ft2 ",) | (1254,54,bar,,,,"ft2 ",) | (1254,54,bar,,,,"ft2 ",) | 1254 | 54 | bar | | | | ft2 | | (54,55,AAA054) | 54 | 55 | AAA054
+ (1272,72,foo,,,,"ft2 ",) | (1272,72,bar,,,,"ft2 ",) | (1272,72,bar,,,,"ft2 ",) | 1272 | 72 | bar | | | | ft2 | | (72,73,AAA072) | 72 | 73 | AAA072
+ (1290,90,foo,,,,"ft2 ",) | (1290,90,bar,,,,"ft2 ",) | (1290,90,bar,,,,"ft2 ",) | 1290 | 90 | bar | | | | ft2 | | (90,91,AAA090) | 90 | 91 | AAA090
+(16 rows)
+
+ROLLBACK;
EXPLAIN (verbose, costs off)
DELETE FROM ft2
USING ft4 LEFT JOIN ft5 ON (ft4.c1 = ft5.c1)
INSERT INTO ft2 (c1,c2,c3) SELECT c1+1000,c2+100, c3 || c3 FROM ft2 LIMIT 20;
INSERT INTO ft2 (c1,c2,c3) SELECT c1+1000,c2+100, c3 || c3 FROM ft2 LIMIT 20;
INSERT INTO ft2 (c1,c2,c3)
- VALUES (1101,201,'aaa'), (1102,202,'bbb'), (1103,203,'ccc') RETURNING *;
+ VALUES (1101,201,'aaa'), (1102,202,'bbb'), (1103,203,'ccc') RETURNING old, new, old.*, new.*;
INSERT INTO ft2 (c1,c2,c3) VALUES (1104,204,'ddd'), (1105,205,'eee');
EXPLAIN (verbose, costs off)
UPDATE ft2 SET c2 = c2 + 300, c3 = c3 || '_update3' WHERE c1 % 10 = 3; -- can be pushed down
EXPLAIN (verbose, costs off)
UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7' WHERE c1 % 10 = 7 RETURNING *; -- can be pushed down
UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7' WHERE c1 % 10 = 7 RETURNING *;
+BEGIN;
+ EXPLAIN (verbose, costs off)
+ UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7b' WHERE c1 % 10 = 7 AND c1 < 40
+ RETURNING old.*, new.*; -- can't be pushed down
+ UPDATE ft2 SET c2 = c2 + 400, c3 = c3 || '_update7b' WHERE c1 % 10 = 7 AND c1 < 40
+ RETURNING old.*, new.*;
+ROLLBACK;
EXPLAIN (verbose, costs off)
UPDATE ft2 SET c2 = ft2.c2 + 500, c3 = ft2.c3 || '_update9', c7 = DEFAULT
FROM ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 9; -- can be pushed down
EXPLAIN (verbose, costs off)
DELETE FROM ft2 WHERE c1 % 10 = 5 RETURNING c1, c4; -- can be pushed down
DELETE FROM ft2 WHERE c1 % 10 = 5 RETURNING c1, c4;
+BEGIN;
+ EXPLAIN (verbose, costs off)
+ DELETE FROM ft2 WHERE c1 % 10 = 6 AND c1 < 40 RETURNING old.c1, c4; -- can't be pushed down
+ DELETE FROM ft2 WHERE c1 % 10 = 6 AND c1 < 40 RETURNING old.c1, c4;
+ROLLBACK;
EXPLAIN (verbose, costs off)
DELETE FROM ft2 USING ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 2; -- can be pushed down
DELETE FROM ft2 USING ft1 WHERE ft1.c1 = ft2.c2 AND ft1.c1 % 10 = 2;
FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
WHERE ft2.c1 > 1200 AND ft2.c2 = ft4.c1
RETURNING ft2, ft2.*, ft4, ft4.*;
+BEGIN;
+ EXPLAIN (verbose, costs off)
+ UPDATE ft2 SET c3 = 'bar'
+ FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
+ WHERE ft2.c1 > 1200 AND ft2.c2 = ft4.c1
+ RETURNING old, new, ft2, ft2.*, ft4, ft4.*; -- can't be pushed down
+ UPDATE ft2 SET c3 = 'bar'
+ FROM ft4 INNER JOIN ft5 ON (ft4.c1 = ft5.c1)
+ WHERE ft2.c1 > 1200 AND ft2.c2 = ft4.c1
+ RETURNING old, new, ft2, ft2.*, ft4, ft4.*;
+ROLLBACK;
EXPLAIN (verbose, costs off)
DELETE FROM ft2
USING ft4 LEFT JOIN ft5 ON (ft4.c1 = ft5.c1)
</para>
<para>
- In an <command>INSERT</command>, the data available to <literal>RETURNING</literal> is
+ In an <command>INSERT</command>, the default data available to
+ <literal>RETURNING</literal> is
the row as it was inserted. This is not so useful in trivial inserts,
since it would just repeat the data provided by the client. But it can
be very handy when relying on computed default values. For example,
</para>
<para>
- In an <command>UPDATE</command>, the data available to <literal>RETURNING</literal> is
+ In an <command>UPDATE</command>, the default data available to
+ <literal>RETURNING</literal> is
the new content of the modified row. For example:
<programlisting>
UPDATE products SET price = price * 1.10
</para>
<para>
- In a <command>DELETE</command>, the data available to <literal>RETURNING</literal> is
+ In a <command>DELETE</command>, the default data available to
+ <literal>RETURNING</literal> is
the content of the deleted row. For example:
<programlisting>
DELETE FROM products
</para>
<para>
- In a <command>MERGE</command>, the data available to <literal>RETURNING</literal> is
+ In a <command>MERGE</command>, the default data available to
+ <literal>RETURNING</literal> is
the content of the source row plus the content of the inserted, updated, or
deleted target row. Since it is quite common for the source and target to
have many of the same columns, specifying <literal>RETURNING *</literal>
</programlisting>
</para>
+ <para>
+ In each of these commands, it is also possible to explicitly return the
+ old and new content of the modified row. For example:
+<programlisting>
+UPDATE products SET price = price * 1.10
+ WHERE price <= 99.99
+ RETURNING name, old.price AS old_price, new.price AS new_price,
+ new.price - old.price AS price_change;
+</programlisting>
+ In this example, writing <literal>new.price</literal> is the same as
+ just writing <literal>price</literal>, but it makes the meaning clearer.
+ </para>
+
+ <para>
+ This syntax for returning old and new values is available in
+ <command>INSERT</command>, <command>UPDATE</command>,
+ <command>DELETE</command>, and <command>MERGE</command> commands, but
+ typically old values will be <literal>NULL</literal> for an
+ <command>INSERT</command>, and new values will be <literal>NULL</literal>
+ for a <command>DELETE</command>. However, there are situations where it
+ can still be useful for those commands. For example, in an
+ <command>INSERT</command> with an
+ <link linkend="sql-on-conflict"><literal>ON CONFLICT DO UPDATE</literal></link>
+ clause, the old values will be non-<literal>NULL</literal> for conflicting
+ rows. Similarly, if a <command>DELETE</command> is turned into an
+ <command>UPDATE</command> by a <link linkend="sql-createrule">rewrite rule</link>,
+ the new values may be non-<literal>NULL</literal>.
+ </para>
+
<para>
If there are triggers (<xref linkend="triggers"/>) on the target table,
the data available to <literal>RETURNING</literal> is the row as modified by
DELETE FROM [ ONLY ] <replaceable class="parameter">table_name</replaceable> [ * ] [ [ AS ] <replaceable class="parameter">alias</replaceable> ]
[ USING <replaceable class="parameter">from_item</replaceable> [, ...] ]
[ WHERE <replaceable class="parameter">condition</replaceable> | WHERE CURRENT OF <replaceable class="parameter">cursor_name</replaceable> ]
- [ RETURNING { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
+ [ RETURNING [ WITH ( { OLD | NEW } AS <replaceable class="parameter">output_alias</replaceable> [, ...] ) ]
+ { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
</synopsis>
</refsynopsisdiv>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">output_alias</replaceable></term>
+ <listitem>
+ <para>
+ An optional substitute name for <literal>OLD</literal> or
+ <literal>NEW</literal> rows in the <literal>RETURNING</literal> list.
+ </para>
+
+ <para>
+ By default, old values from the target table can be returned by writing
+ <literal>OLD.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>OLD.*</literal>, and new values can be returned by writing
+ <literal>NEW.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>NEW.*</literal>. When an alias is provided, these names are
+ hidden and the old or new rows must be referred to using the alias.
+ For example <literal>RETURNING WITH (OLD AS o, NEW AS n) o.*, n.*</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">output_expression</replaceable></term>
<listitem>
or table(s) listed in <literal>USING</literal>.
Write <literal>*</literal> to return all columns.
</para>
+
+ <para>
+ A column name or <literal>*</literal> may be qualified using
+ <literal>OLD</literal> or <literal>NEW</literal>, or the corresponding
+ <replaceable class="parameter">output_alias</replaceable> for
+ <literal>OLD</literal> or <literal>NEW</literal>, to cause old or new
+ values to be returned. An unqualified column name, or
+ <literal>*</literal>, or a column name or <literal>*</literal> qualified
+ using the target table name or alias will return old values.
+ </para>
+
+ <para>
+ For a simple <command>DELETE</command>, all new values will be
+ <literal>NULL</literal>. However, if an <literal>ON DELETE</literal>
+ rule causes an <command>INSERT</command> or <command>UPDATE</command>
+ to be executed instead, the new values may be non-<literal>NULL</literal>.
+ </para>
</listitem>
</varlistentry>
[ OVERRIDING { SYSTEM | USER } VALUE ]
{ DEFAULT VALUES | VALUES ( { <replaceable class="parameter">expression</replaceable> | DEFAULT } [, ...] ) [, ...] | <replaceable class="parameter">query</replaceable> }
[ ON CONFLICT [ <replaceable class="parameter">conflict_target</replaceable> ] <replaceable class="parameter">conflict_action</replaceable> ]
- [ RETURNING { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
+ [ RETURNING [ WITH ( { OLD | NEW } AS <replaceable class="parameter">output_alias</replaceable> [, ...] ) ]
+ { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
<phrase>where <replaceable class="parameter">conflict_target</replaceable> can be one of:</phrase>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">output_alias</replaceable></term>
+ <listitem>
+ <para>
+ An optional substitute name for <literal>OLD</literal> or
+ <literal>NEW</literal> rows in the <literal>RETURNING</literal> list.
+ </para>
+
+ <para>
+ By default, old values from the target table can be returned by writing
+ <literal>OLD.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>OLD.*</literal>, and new values can be returned by writing
+ <literal>NEW.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>NEW.*</literal>. When an alias is provided, these names are
+ hidden and the old or new rows must be referred to using the alias.
+ For example <literal>RETURNING WITH (OLD AS o, NEW AS n) o.*, n.*</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">output_expression</replaceable></term>
<listitem>
<literal>*</literal> to return all columns of the inserted or updated
row(s).
</para>
+
+ <para>
+ A column name or <literal>*</literal> may be qualified using
+ <literal>OLD</literal> or <literal>NEW</literal>, or the corresponding
+ <replaceable class="parameter">output_alias</replaceable> for
+ <literal>OLD</literal> or <literal>NEW</literal>, to cause old or new
+ values to be returned. An unqualified column name, or
+ <literal>*</literal>, or a column name or <literal>*</literal>
+ qualified using the target table name or alias will return new values.
+ </para>
+
+ <para>
+ For a simple <command>INSERT</command>, all old values will be
+ <literal>NULL</literal>. However, for an <command>INSERT</command>
+ with an <literal>ON CONFLICT DO UPDATE</literal> clause, the old
+ values may be non-<literal>NULL</literal>.
+ </para>
</listitem>
</varlistentry>
INSERT INTO distributors (did, dname)
VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname;
+</programlisting>
+ </para>
+ <para>
+ Insert or update new distributors as above, returning information
+ about any existing values that were updated, together with the new data
+ inserted. Note that the returned values for <literal>old_did</literal>
+ and <literal>old_dname</literal> will be <literal>NULL</literal> for
+ non-conflicting rows:
+<programlisting>
+INSERT INTO distributors (did, dname)
+ VALUES (5, 'Gizmo Transglobal'), (6, 'Associated Computing, Inc')
+ ON CONFLICT (did) DO UPDATE SET dname = EXCLUDED.dname
+ RETURNING old.did AS old_did, old.dname AS old_dname,
+ new.did AS new_did, new.dname AS new_dname;
</programlisting>
</para>
<para>
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> [...]
-[ RETURNING { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
+[ RETURNING [ WITH ( { OLD | NEW } AS <replaceable class="parameter">output_alias</replaceable> [, ...] ) ]
+ { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
<phrase>where <replaceable class="parameter">data_source</replaceable> is:</phrase>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">output_alias</replaceable></term>
+ <listitem>
+ <para>
+ An optional substitute name for <literal>OLD</literal> or
+ <literal>NEW</literal> rows in the <literal>RETURNING</literal> list.
+ </para>
+ <para>
+ By default, old values from the target table can be returned by writing
+ <literal>OLD.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>OLD.*</literal>, and new values can be returned by writing
+ <literal>NEW.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>NEW.*</literal>. When an alias is provided, these names are
+ hidden and the old or new rows must be referred to using the alias.
+ For example <literal>RETURNING WITH (OLD AS o, NEW AS n) o.*, n.*</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">output_expression</replaceable></term>
<listitem>
qualifying the <literal>*</literal> with the name or alias of the source
or target table.
</para>
+ <para>
+ A column name or <literal>*</literal> may also be qualified using
+ <literal>OLD</literal> or <literal>NEW</literal>, or the corresponding
+ <replaceable class="parameter">output_alias</replaceable> for
+ <literal>OLD</literal> or <literal>NEW</literal>, to cause old or new
+ values from the target table to be returned. An unqualified column
+ name from the target table, or a column name or <literal>*</literal>
+ qualified using the target table name or alias will return new values
+ for <literal>INSERT</literal> and <literal>UPDATE</literal> actions, and
+ old values for <literal>DELETE</literal> actions.
+ </para>
</listitem>
</varlistentry>
UPDATE SET stock = w.stock + s.stock_delta
WHEN MATCHED THEN
DELETE
-RETURNING merge_action(), w.*;
+RETURNING merge_action(), w.winename, old.stock AS old_stock, new.stock AS new_stock;
</programlisting>
The <literal>wine_stock_changes</literal> table might be, for example, a
} [, ...]
[ FROM <replaceable class="parameter">from_item</replaceable> [, ...] ]
[ WHERE <replaceable class="parameter">condition</replaceable> | WHERE CURRENT OF <replaceable class="parameter">cursor_name</replaceable> ]
- [ RETURNING { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
+ [ RETURNING [ WITH ( { OLD | NEW } AS <replaceable class="parameter">output_alias</replaceable> [, ...] ) ]
+ { * | <replaceable class="parameter">output_expression</replaceable> [ [ AS ] <replaceable class="parameter">output_name</replaceable> ] } [, ...] ]
</synopsis>
</refsynopsisdiv>
</listitem>
</varlistentry>
+ <varlistentry>
+ <term><replaceable class="parameter">output_alias</replaceable></term>
+ <listitem>
+ <para>
+ An optional substitute name for <literal>OLD</literal> or
+ <literal>NEW</literal> rows in the <literal>RETURNING</literal> list.
+ </para>
+
+ <para>
+ By default, old values from the target table can be returned by writing
+ <literal>OLD.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>OLD.*</literal>, and new values can be returned by writing
+ <literal>NEW.<replaceable class="parameter">column_name</replaceable></literal>
+ or <literal>NEW.*</literal>. When an alias is provided, these names are
+ hidden and the old or new rows must be referred to using the alias.
+ For example <literal>RETURNING WITH (OLD AS o, NEW AS n) o.*, n.*</literal>.
+ </para>
+ </listitem>
+ </varlistentry>
+
<varlistentry>
<term><replaceable class="parameter">output_expression</replaceable></term>
<listitem>
or table(s) listed in <literal>FROM</literal>.
Write <literal>*</literal> to return all columns.
</para>
+
+ <para>
+ A column name or <literal>*</literal> may be qualified using
+ <literal>OLD</literal> or <literal>NEW</literal>, or the corresponding
+ <replaceable class="parameter">output_alias</replaceable> for
+ <literal>OLD</literal> or <literal>NEW</literal>, to cause old or new
+ values to be returned. An unqualified column name, or
+ <literal>*</literal>, or a column name or <literal>*</literal> qualified
+ using the target table name or alias will return new values.
+ </para>
</listitem>
</varlistentry>
</para>
<para>
- Perform the same operation and return the updated entries:
+ Perform the same operation and return the updated entries, and the old
+ precipitation value:
<programlisting>
UPDATE weather SET temp_lo = temp_lo+1, temp_hi = temp_lo+15, prcp = DEFAULT
WHERE city = 'San Francisco' AND date = '2003-07-03'
- RETURNING temp_lo, temp_hi, prcp;
+ RETURNING temp_lo, temp_hi, prcp, old.prcp AS old_prcp;
</programlisting>
</para>
<literal>RETURNING</literal> clause is simply ignored for <command>INSERT</command>.
</para>
+ <para>
+ Note that in the <literal>RETURNING</literal> clause of a rule,
+ <literal>OLD</literal> and <literal>NEW</literal> refer to the
+ pseudorelations added as extra range table entries to the rewritten
+ query, rather than old/new rows in the result relation. Thus, for
+ example, in a rule supporting <command>UPDATE</command> queries on this
+ view, if the <literal>RETURNING</literal> clause contained
+ <literal>old.sl_name</literal>, the old name would always be returned,
+ regardless of whether the <literal>RETURNING</literal> clause in the
+ query on the view specified <literal>OLD</literal> or <literal>NEW</literal>,
+ which might be confusing. To avoid this confusion, and support returning
+ old and new values in queries on the view, the <literal>RETURNING</literal>
+ clause in the rule definition should refer to entries from the result
+ relation such as <literal>shoelace_data.sl_name</literal>, without
+ specifying <literal>OLD</literal> or <literal>NEW</literal>.
+ </para>
+
<para>
Now assume that once in a while, a pack of shoelaces arrives at
the shop and a big parts list along with it. But you don't want
typedef struct ExprSetupInfo
{
- /* Highest attribute numbers fetched from inner/outer/scan tuple slots: */
+ /*
+ * Highest attribute numbers fetched from inner/outer/scan/old/new tuple
+ * slots:
+ */
AttrNumber last_inner;
AttrNumber last_outer;
AttrNumber last_scan;
+ AttrNumber last_old;
+ AttrNumber last_new;
/* MULTIEXPR SubPlan nodes appearing in the expression: */
List *multiexpr_subplans;
} ExprSetupInfo;
/* INDEX_VAR is handled by default case */
default:
- /* get the tuple from the relation being scanned */
- scratch.opcode = EEOP_ASSIGN_SCAN_VAR;
+
+ /*
+ * Get the tuple from the relation being scanned, or the
+ * old/new tuple slot, if old/new values were requested.
+ */
+ switch (variable->varreturningtype)
+ {
+ case VAR_RETURNING_DEFAULT:
+ scratch.opcode = EEOP_ASSIGN_SCAN_VAR;
+ break;
+ case VAR_RETURNING_OLD:
+ scratch.opcode = EEOP_ASSIGN_OLD_VAR;
+ state->flags |= EEO_FLAG_HAS_OLD;
+ break;
+ case VAR_RETURNING_NEW:
+ scratch.opcode = EEOP_ASSIGN_NEW_VAR;
+ state->flags |= EEO_FLAG_HAS_NEW;
+ break;
+ }
break;
}
int nAssignableCols;
bool sawJunk;
Bitmapset *assignedCols;
- ExprSetupInfo deform = {0, 0, 0, NIL};
+ ExprSetupInfo deform = {0, 0, 0, 0, 0, NIL};
ExprEvalStep scratch = {0};
int outerattnum;
ListCell *lc,
/* system column */
scratch.d.var.attnum = variable->varattno;
scratch.d.var.vartype = variable->vartype;
+ scratch.d.var.varreturningtype = variable->varreturningtype;
switch (variable->varno)
{
case INNER_VAR:
/* INDEX_VAR is handled by default case */
default:
- scratch.opcode = EEOP_SCAN_SYSVAR;
+ switch (variable->varreturningtype)
+ {
+ case VAR_RETURNING_DEFAULT:
+ scratch.opcode = EEOP_SCAN_SYSVAR;
+ break;
+ case VAR_RETURNING_OLD:
+ scratch.opcode = EEOP_OLD_SYSVAR;
+ state->flags |= EEO_FLAG_HAS_OLD;
+ break;
+ case VAR_RETURNING_NEW:
+ scratch.opcode = EEOP_NEW_SYSVAR;
+ state->flags |= EEO_FLAG_HAS_NEW;
+ break;
+ }
break;
}
}
/* regular user column */
scratch.d.var.attnum = variable->varattno - 1;
scratch.d.var.vartype = variable->vartype;
+ scratch.d.var.varreturningtype = variable->varreturningtype;
switch (variable->varno)
{
case INNER_VAR:
/* INDEX_VAR is handled by default case */
default:
- scratch.opcode = EEOP_SCAN_VAR;
+ switch (variable->varreturningtype)
+ {
+ case VAR_RETURNING_DEFAULT:
+ scratch.opcode = EEOP_SCAN_VAR;
+ break;
+ case VAR_RETURNING_OLD:
+ scratch.opcode = EEOP_OLD_VAR;
+ state->flags |= EEO_FLAG_HAS_OLD;
+ break;
+ case VAR_RETURNING_NEW:
+ scratch.opcode = EEOP_NEW_VAR;
+ state->flags |= EEO_FLAG_HAS_NEW;
+ break;
+ }
break;
}
}
break;
}
+ case T_ReturningExpr:
+ {
+ ReturningExpr *rexpr = (ReturningExpr *) node;
+ int retstep;
+
+ /* Skip expression evaluation if OLD/NEW row doesn't exist */
+ scratch.opcode = EEOP_RETURNINGEXPR;
+ scratch.d.returningexpr.nullflag = rexpr->retold ?
+ EEO_FLAG_OLD_IS_NULL : EEO_FLAG_NEW_IS_NULL;
+ scratch.d.returningexpr.jumpdone = -1; /* set below */
+ ExprEvalPushStep(state, &scratch);
+ retstep = state->steps_len - 1;
+
+ /* Steps to evaluate expression to return */
+ ExecInitExprRec(rexpr->retexpr, state, resv, resnull);
+
+ /* Jump target used if OLD/NEW row doesn't exist */
+ state->steps[retstep].d.returningexpr.jumpdone = state->steps_len;
+
+ /* Update ExprState flags */
+ if (rexpr->retold)
+ state->flags |= EEO_FLAG_HAS_OLD;
+ else
+ state->flags |= EEO_FLAG_HAS_NEW;
+
+ break;
+ }
+
default:
elog(ERROR, "unrecognized node type: %d",
(int) nodeTag(node));
static void
ExecCreateExprSetupSteps(ExprState *state, Node *node)
{
- ExprSetupInfo info = {0, 0, 0, NIL};
+ ExprSetupInfo info = {0, 0, 0, 0, 0, NIL};
/* Prescan to find out what we need. */
expr_setup_walker(node, &info);
scratch.resnull = NULL;
/*
- * Add steps deforming the ExprState's inner/outer/scan slots as much as
- * required by any Vars appearing in the expression.
+ * Add steps deforming the ExprState's inner/outer/scan/old/new slots as
+ * much as required by any Vars appearing in the expression.
*/
if (info->last_inner > 0)
{
if (ExecComputeSlotInfo(state, &scratch))
ExprEvalPushStep(state, &scratch);
}
+ if (info->last_old > 0)
+ {
+ scratch.opcode = EEOP_OLD_FETCHSOME;
+ scratch.d.fetch.last_var = info->last_old;
+ scratch.d.fetch.fixed = false;
+ scratch.d.fetch.kind = NULL;
+ scratch.d.fetch.known_desc = NULL;
+ if (ExecComputeSlotInfo(state, &scratch))
+ ExprEvalPushStep(state, &scratch);
+ }
+ if (info->last_new > 0)
+ {
+ scratch.opcode = EEOP_NEW_FETCHSOME;
+ scratch.d.fetch.last_var = info->last_new;
+ scratch.d.fetch.fixed = false;
+ scratch.d.fetch.kind = NULL;
+ scratch.d.fetch.known_desc = NULL;
+ if (ExecComputeSlotInfo(state, &scratch))
+ ExprEvalPushStep(state, &scratch);
+ }
/*
* Add steps to execute any MULTIEXPR SubPlans appearing in the
/* INDEX_VAR is handled by default case */
default:
- info->last_scan = Max(info->last_scan, attnum);
+ switch (variable->varreturningtype)
+ {
+ case VAR_RETURNING_DEFAULT:
+ info->last_scan = Max(info->last_scan, attnum);
+ break;
+ case VAR_RETURNING_OLD:
+ info->last_old = Max(info->last_old, attnum);
+ break;
+ case VAR_RETURNING_NEW:
+ info->last_new = Max(info->last_new, attnum);
+ break;
+ }
break;
}
return false;
* evaluation of the expression will have the same type of slot, with an
* equivalent descriptor.
*
+ * EEOP_OLD_FETCHSOME and EEOP_NEW_FETCHSOME are used to process RETURNING, if
+ * OLD/NEW columns are referred to explicitly. In both cases, the tuple
+ * descriptor comes from the parent scan node, so we treat them the same as
+ * EEOP_SCAN_FETCHSOME.
+ *
* Returns true if the deforming step is required, false otherwise.
*/
static bool
Assert(opcode == EEOP_INNER_FETCHSOME ||
opcode == EEOP_OUTER_FETCHSOME ||
- opcode == EEOP_SCAN_FETCHSOME);
+ opcode == EEOP_SCAN_FETCHSOME ||
+ opcode == EEOP_OLD_FETCHSOME ||
+ opcode == EEOP_NEW_FETCHSOME);
if (op->d.fetch.known_desc != NULL)
{
desc = ExecGetResultType(os);
}
}
- else if (opcode == EEOP_SCAN_FETCHSOME)
+ else if (opcode == EEOP_SCAN_FETCHSOME ||
+ opcode == EEOP_OLD_FETCHSOME ||
+ opcode == EEOP_NEW_FETCHSOME)
{
desc = parent->scandesc;
scratch->d.wholerow.tupdesc = NULL; /* filled at runtime */
scratch->d.wholerow.junkFilter = NULL;
+ /* update ExprState flags if Var refers to OLD/NEW */
+ if (variable->varreturningtype == VAR_RETURNING_OLD)
+ state->flags |= EEO_FLAG_HAS_OLD;
+ else if (variable->varreturningtype == VAR_RETURNING_NEW)
+ state->flags |= EEO_FLAG_HAS_NEW;
+
/*
* If the input tuple came from a subquery, it might contain "resjunk"
* columns (such as GROUP BY or ORDER BY columns), which we don't want to
PlanState *parent = &aggstate->ss.ps;
ExprEvalStep scratch = {0};
bool isCombine = DO_AGGSPLIT_COMBINE(aggstate->aggsplit);
- ExprSetupInfo deform = {0, 0, 0, NIL};
+ ExprSetupInfo deform = {0, 0, 0, 0, 0, NIL};
state->expr = (Expr *) aggstate;
state->parent = parent;
scratch.resnull = &fcinfo->args[0].isnull;
scratch.d.var.attnum = attnum;
scratch.d.var.vartype = TupleDescAttr(desc, attnum)->atttypid;
+ scratch.d.var.varreturningtype = VAR_RETURNING_DEFAULT;
ExprEvalPushStep(state, &scratch);
scratch.opcode = EEOP_INNER_VAR;
scratch.d.var.attnum = attno - 1;
scratch.d.var.vartype = latt->atttypid;
+ scratch.d.var.varreturningtype = VAR_RETURNING_DEFAULT;
scratch.resvalue = &fcinfo->args[0].value;
scratch.resnull = &fcinfo->args[0].isnull;
ExprEvalPushStep(state, &scratch);
scratch.opcode = EEOP_OUTER_VAR;
scratch.d.var.attnum = attno - 1;
scratch.d.var.vartype = ratt->atttypid;
+ scratch.d.var.varreturningtype = VAR_RETURNING_DEFAULT;
scratch.resvalue = &fcinfo->args[1].value;
scratch.resnull = &fcinfo->args[1].isnull;
ExprEvalPushStep(state, &scratch);
scratch.opcode = EEOP_INNER_VAR;
scratch.d.var.attnum = attno;
scratch.d.var.vartype = att->atttypid;
+ scratch.d.var.varreturningtype = VAR_RETURNING_DEFAULT;
scratch.resvalue = &fcinfo->args[0].value;
scratch.resnull = &fcinfo->args[0].isnull;
ExprEvalPushStep(state, &scratch);
scratch.opcode = EEOP_OUTER_VAR;
scratch.d.var.attnum = attno;
scratch.d.var.vartype = att->atttypid;
+ scratch.d.var.varreturningtype = VAR_RETURNING_DEFAULT;
scratch.resvalue = &fcinfo->args[1].value;
scratch.resnull = &fcinfo->args[1].isnull;
ExprEvalPushStep(state, &scratch);
TupleTableSlot *innerslot;
TupleTableSlot *outerslot;
TupleTableSlot *scanslot;
+ TupleTableSlot *oldslot;
+ TupleTableSlot *newslot;
/*
* This array has to be in the same order as enum ExprEvalOp.
&&CASE_EEOP_INNER_FETCHSOME,
&&CASE_EEOP_OUTER_FETCHSOME,
&&CASE_EEOP_SCAN_FETCHSOME,
+ &&CASE_EEOP_OLD_FETCHSOME,
+ &&CASE_EEOP_NEW_FETCHSOME,
&&CASE_EEOP_INNER_VAR,
&&CASE_EEOP_OUTER_VAR,
&&CASE_EEOP_SCAN_VAR,
+ &&CASE_EEOP_OLD_VAR,
+ &&CASE_EEOP_NEW_VAR,
&&CASE_EEOP_INNER_SYSVAR,
&&CASE_EEOP_OUTER_SYSVAR,
&&CASE_EEOP_SCAN_SYSVAR,
+ &&CASE_EEOP_OLD_SYSVAR,
+ &&CASE_EEOP_NEW_SYSVAR,
&&CASE_EEOP_WHOLEROW,
&&CASE_EEOP_ASSIGN_INNER_VAR,
&&CASE_EEOP_ASSIGN_OUTER_VAR,
&&CASE_EEOP_ASSIGN_SCAN_VAR,
+ &&CASE_EEOP_ASSIGN_OLD_VAR,
+ &&CASE_EEOP_ASSIGN_NEW_VAR,
&&CASE_EEOP_ASSIGN_TMP,
&&CASE_EEOP_ASSIGN_TMP_MAKE_RO,
&&CASE_EEOP_CONST,
&&CASE_EEOP_SQLVALUEFUNCTION,
&&CASE_EEOP_CURRENTOFEXPR,
&&CASE_EEOP_NEXTVALUEEXPR,
+ &&CASE_EEOP_RETURNINGEXPR,
&&CASE_EEOP_ARRAYEXPR,
&&CASE_EEOP_ARRAYCOERCE,
&&CASE_EEOP_ROW,
innerslot = econtext->ecxt_innertuple;
outerslot = econtext->ecxt_outertuple;
scanslot = econtext->ecxt_scantuple;
+ oldslot = econtext->ecxt_oldtuple;
+ newslot = econtext->ecxt_newtuple;
#if defined(EEO_USE_COMPUTED_GOTO)
EEO_DISPATCH();
EEO_NEXT();
}
+ EEO_CASE(EEOP_OLD_FETCHSOME)
+ {
+ CheckOpSlotCompatibility(op, oldslot);
+
+ slot_getsomeattrs(oldslot, op->d.fetch.last_var);
+
+ EEO_NEXT();
+ }
+
+ EEO_CASE(EEOP_NEW_FETCHSOME)
+ {
+ CheckOpSlotCompatibility(op, newslot);
+
+ slot_getsomeattrs(newslot, op->d.fetch.last_var);
+
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_INNER_VAR)
{
int attnum = op->d.var.attnum;
EEO_NEXT();
}
+ EEO_CASE(EEOP_OLD_VAR)
+ {
+ int attnum = op->d.var.attnum;
+
+ /* See EEOP_INNER_VAR comments */
+
+ Assert(attnum >= 0 && attnum < oldslot->tts_nvalid);
+ *op->resvalue = oldslot->tts_values[attnum];
+ *op->resnull = oldslot->tts_isnull[attnum];
+
+ EEO_NEXT();
+ }
+
+ EEO_CASE(EEOP_NEW_VAR)
+ {
+ int attnum = op->d.var.attnum;
+
+ /* See EEOP_INNER_VAR comments */
+
+ Assert(attnum >= 0 && attnum < newslot->tts_nvalid);
+ *op->resvalue = newslot->tts_values[attnum];
+ *op->resnull = newslot->tts_isnull[attnum];
+
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_INNER_SYSVAR)
{
ExecEvalSysVar(state, op, econtext, innerslot);
EEO_NEXT();
}
+ EEO_CASE(EEOP_OLD_SYSVAR)
+ {
+ ExecEvalSysVar(state, op, econtext, oldslot);
+ EEO_NEXT();
+ }
+
+ EEO_CASE(EEOP_NEW_SYSVAR)
+ {
+ ExecEvalSysVar(state, op, econtext, newslot);
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_WHOLEROW)
{
/* too complex for an inline implementation */
EEO_NEXT();
}
+ EEO_CASE(EEOP_ASSIGN_OLD_VAR)
+ {
+ int resultnum = op->d.assign_var.resultnum;
+ int attnum = op->d.assign_var.attnum;
+
+ /*
+ * We do not need CheckVarSlotCompatibility here; that was taken
+ * care of at compilation time. But see EEOP_INNER_VAR comments.
+ */
+ Assert(attnum >= 0 && attnum < oldslot->tts_nvalid);
+ Assert(resultnum >= 0 && resultnum < resultslot->tts_tupleDescriptor->natts);
+ resultslot->tts_values[resultnum] = oldslot->tts_values[attnum];
+ resultslot->tts_isnull[resultnum] = oldslot->tts_isnull[attnum];
+
+ EEO_NEXT();
+ }
+
+ EEO_CASE(EEOP_ASSIGN_NEW_VAR)
+ {
+ int resultnum = op->d.assign_var.resultnum;
+ int attnum = op->d.assign_var.attnum;
+
+ /*
+ * We do not need CheckVarSlotCompatibility here; that was taken
+ * care of at compilation time. But see EEOP_INNER_VAR comments.
+ */
+ Assert(attnum >= 0 && attnum < newslot->tts_nvalid);
+ Assert(resultnum >= 0 && resultnum < resultslot->tts_tupleDescriptor->natts);
+ resultslot->tts_values[resultnum] = newslot->tts_values[attnum];
+ resultslot->tts_isnull[resultnum] = newslot->tts_isnull[attnum];
+
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_ASSIGN_TMP)
{
int resultnum = op->d.assign_tmp.resultnum;
EEO_NEXT();
}
+ EEO_CASE(EEOP_RETURNINGEXPR)
+ {
+ /*
+ * The next op actually evaluates the expression. If the OLD/NEW
+ * row doesn't exist, skip that and return NULL.
+ */
+ if (state->flags & op->d.returningexpr.nullflag)
+ {
+ *op->resvalue = (Datum) 0;
+ *op->resnull = true;
+
+ EEO_JUMP(op->d.returningexpr.jumpdone);
+ }
+
+ EEO_NEXT();
+ }
+
EEO_CASE(EEOP_ARRAYEXPR)
{
/* too complex for an inline implementation */
TupleTableSlot *innerslot;
TupleTableSlot *outerslot;
TupleTableSlot *scanslot;
+ TupleTableSlot *oldslot;
+ TupleTableSlot *newslot;
innerslot = econtext->ecxt_innertuple;
outerslot = econtext->ecxt_outertuple;
scanslot = econtext->ecxt_scantuple;
+ oldslot = econtext->ecxt_oldtuple;
+ newslot = econtext->ecxt_newtuple;
for (int i = 0; i < state->steps_len; i++)
{
CheckVarSlotCompatibility(scanslot, attnum + 1, op->d.var.vartype);
break;
}
+
+ case EEOP_OLD_VAR:
+ {
+ int attnum = op->d.var.attnum;
+
+ CheckVarSlotCompatibility(oldslot, attnum + 1, op->d.var.vartype);
+ break;
+ }
+
+ case EEOP_NEW_VAR:
+ {
+ int attnum = op->d.var.attnum;
+
+ CheckVarSlotCompatibility(newslot, attnum + 1, op->d.var.vartype);
+ break;
+ }
default:
break;
}
ExecEvalWholeRowVar(ExprState *state, ExprEvalStep *op, ExprContext *econtext)
{
Var *variable = op->d.wholerow.var;
- TupleTableSlot *slot;
+ TupleTableSlot *slot = NULL;
TupleDesc output_tupdesc;
MemoryContext oldcontext;
HeapTupleHeader dtuple;
/* INDEX_VAR is handled by default case */
default:
- /* get the tuple from the relation being scanned */
- slot = econtext->ecxt_scantuple;
+
+ /*
+ * Get the tuple from the relation being scanned.
+ *
+ * By default, this uses the "scan" tuple slot, but a wholerow Var
+ * in the RETURNING list may explicitly refer to OLD/NEW. If the
+ * OLD/NEW row doesn't exist, we just return NULL.
+ */
+ switch (variable->varreturningtype)
+ {
+ case VAR_RETURNING_DEFAULT:
+ slot = econtext->ecxt_scantuple;
+ break;
+
+ case VAR_RETURNING_OLD:
+ if (state->flags & EEO_FLAG_OLD_IS_NULL)
+ {
+ *op->resvalue = (Datum) 0;
+ *op->resnull = true;
+ return;
+ }
+ slot = econtext->ecxt_oldtuple;
+ break;
+
+ case VAR_RETURNING_NEW:
+ if (state->flags & EEO_FLAG_NEW_IS_NULL)
+ {
+ *op->resvalue = (Datum) 0;
+ *op->resnull = true;
+ return;
+ }
+ slot = econtext->ecxt_newtuple;
+ break;
+ }
break;
}
{
Datum d;
+ /* OLD/NEW system attribute is NULL if OLD/NEW row is NULL */
+ if ((op->d.var.varreturningtype == VAR_RETURNING_OLD &&
+ state->flags & EEO_FLAG_OLD_IS_NULL) ||
+ (op->d.var.varreturningtype == VAR_RETURNING_NEW &&
+ state->flags & EEO_FLAG_NEW_IS_NULL))
+ {
+ *op->resvalue = (Datum) 0;
+ *op->resnull = true;
+ return;
+ }
+
/* slot_getsysattr has sufficient defenses against bad attnums */
d = slot_getsysattr(slot,
op->d.var.attnum,
resultRelInfo->ri_ReturningSlot = NULL;
resultRelInfo->ri_TrigOldSlot = NULL;
resultRelInfo->ri_TrigNewSlot = NULL;
+ resultRelInfo->ri_AllNullSlot = NULL;
resultRelInfo->ri_MergeActions[MERGE_WHEN_MATCHED] = NIL;
resultRelInfo->ri_MergeActions[MERGE_WHEN_NOT_MATCHED_BY_SOURCE] = NIL;
resultRelInfo->ri_MergeActions[MERGE_WHEN_NOT_MATCHED_BY_TARGET] = NIL;
return relInfo->ri_ReturningSlot;
}
+/*
+ * Return a relInfo's all-NULL tuple slot for processing returning tuples.
+ *
+ * Note: this slot is intentionally filled with NULLs in every column, and
+ * should be considered read-only --- the caller must not update it.
+ */
+TupleTableSlot *
+ExecGetAllNullSlot(EState *estate, ResultRelInfo *relInfo)
+{
+ if (relInfo->ri_AllNullSlot == NULL)
+ {
+ Relation rel = relInfo->ri_RelationDesc;
+ MemoryContext oldcontext = MemoryContextSwitchTo(estate->es_query_cxt);
+ TupleTableSlot *slot;
+
+ slot = ExecInitExtraTupleSlot(estate,
+ RelationGetDescr(rel),
+ table_slot_callbacks(rel));
+ ExecStoreAllNullTuple(slot);
+
+ relInfo->ri_AllNullSlot = slot;
+
+ MemoryContextSwitchTo(oldcontext);
+ }
+
+ return relInfo->ri_AllNullSlot;
+}
+
/*
* Return the map needed to convert given child result relation's tuples to
* the rowtype of the query's main target ("root") relation. Note that a
*/
TM_FailureData tmfd;
+ /*
+ * The tuple deleted when doing a cross-partition UPDATE with a RETURNING
+ * clause that refers to OLD columns (converted to the root's tuple
+ * descriptor).
+ */
+ TupleTableSlot *cpDeletedSlot;
+
/*
* The tuple projected by the INSERT's RETURNING clause, when doing a
* cross-partition UPDATE
/*
* ExecProcessReturning --- evaluate a RETURNING list
*
+ * context: context for the ModifyTable operation
* resultRelInfo: current result rel
- * tupleSlot: slot holding tuple actually inserted/updated/deleted
+ * cmdType: operation/merge action performed (INSERT, UPDATE, or DELETE)
+ * oldSlot: slot holding old tuple deleted or updated
+ * newSlot: slot holding new tuple inserted or updated
* planSlot: slot holding tuple returned by top subplan node
*
- * Note: If tupleSlot is NULL, the FDW should have already provided econtext's
- * scan tuple.
+ * Note: If oldSlot and newSlot are NULL, the FDW should have already provided
+ * econtext's scan tuple and its old & new tuples are not needed (FDW direct-
+ * modify is disabled if the RETURNING list refers to any OLD/NEW values).
*
* Returns a slot holding the result tuple
*/
static TupleTableSlot *
-ExecProcessReturning(ResultRelInfo *resultRelInfo,
- TupleTableSlot *tupleSlot,
+ExecProcessReturning(ModifyTableContext *context,
+ ResultRelInfo *resultRelInfo,
+ CmdType cmdType,
+ TupleTableSlot *oldSlot,
+ TupleTableSlot *newSlot,
TupleTableSlot *planSlot)
{
+ EState *estate = context->estate;
ProjectionInfo *projectReturning = resultRelInfo->ri_projectReturning;
ExprContext *econtext = projectReturning->pi_exprContext;
/* Make tuple and any needed join variables available to ExecProject */
- if (tupleSlot)
- econtext->ecxt_scantuple = tupleSlot;
+ switch (cmdType)
+ {
+ case CMD_INSERT:
+ case CMD_UPDATE:
+ /* return new tuple by default */
+ if (newSlot)
+ econtext->ecxt_scantuple = newSlot;
+ break;
+
+ case CMD_DELETE:
+ /* return old tuple by default */
+ if (oldSlot)
+ econtext->ecxt_scantuple = oldSlot;
+ break;
+
+ default:
+ elog(ERROR, "unrecognized commandType: %d", (int) cmdType);
+ }
econtext->ecxt_outertuple = planSlot;
+ /* Make old/new tuples available to ExecProject, if required */
+ if (oldSlot)
+ econtext->ecxt_oldtuple = oldSlot;
+ else if (projectReturning->pi_state.flags & EEO_FLAG_HAS_OLD)
+ econtext->ecxt_oldtuple = ExecGetAllNullSlot(estate, resultRelInfo);
+ else
+ econtext->ecxt_oldtuple = NULL; /* No references to OLD columns */
+
+ if (newSlot)
+ econtext->ecxt_newtuple = newSlot;
+ else if (projectReturning->pi_state.flags & EEO_FLAG_HAS_NEW)
+ econtext->ecxt_newtuple = ExecGetAllNullSlot(estate, resultRelInfo);
+ else
+ econtext->ecxt_newtuple = NULL; /* No references to NEW columns */
+
/*
- * RETURNING expressions might reference the tableoid column, so
- * reinitialize tts_tableOid before evaluating them.
+ * Tell ExecProject whether or not the OLD/NEW rows actually exist. This
+ * information is required to evaluate ReturningExpr nodes and also in
+ * ExecEvalSysVar() and ExecEvalWholeRowVar().
*/
- econtext->ecxt_scantuple->tts_tableOid =
- RelationGetRelid(resultRelInfo->ri_RelationDesc);
+ if (oldSlot == NULL)
+ projectReturning->pi_state.flags |= EEO_FLAG_OLD_IS_NULL;
+ else
+ projectReturning->pi_state.flags &= ~EEO_FLAG_OLD_IS_NULL;
+
+ if (newSlot == NULL)
+ projectReturning->pi_state.flags |= EEO_FLAG_NEW_IS_NULL;
+ else
+ projectReturning->pi_state.flags &= ~EEO_FLAG_NEW_IS_NULL;
/* Compute the RETURNING expressions */
return ExecProject(projectReturning);
/* Process RETURNING if present */
if (resultRelInfo->ri_projectReturning)
- result = ExecProcessReturning(resultRelInfo, slot, planSlot);
+ {
+ TupleTableSlot *oldSlot = NULL;
+
+ /*
+ * If this is part of a cross-partition UPDATE, and the RETURNING list
+ * refers to any OLD columns, ExecDelete() will have saved the tuple
+ * deleted from the original partition, which we must use here to
+ * compute the OLD column values. Otherwise, all OLD column values
+ * will be NULL.
+ */
+ if (context->cpDeletedSlot)
+ {
+ TupleConversionMap *tupconv_map;
+
+ /*
+ * Convert the OLD tuple to the new partition's format/slot, if
+ * needed. Note that ExceDelete() already converted it to the
+ * root's partition's format/slot.
+ */
+ oldSlot = context->cpDeletedSlot;
+ tupconv_map = ExecGetRootToChildMap(resultRelInfo, estate);
+ if (tupconv_map != NULL)
+ {
+ oldSlot = execute_attr_map_slot(tupconv_map->attrMap,
+ oldSlot,
+ ExecGetReturningSlot(estate,
+ resultRelInfo));
+
+ oldSlot->tts_tableOid = context->cpDeletedSlot->tts_tableOid;
+ ItemPointerCopy(&context->cpDeletedSlot->tts_tid, &oldSlot->tts_tid);
+ }
+ }
+
+ result = ExecProcessReturning(context, resultRelInfo, CMD_INSERT,
+ oldSlot, slot, planSlot);
+
+ /*
+ * For a cross-partition UPDATE, release the old tuple, first making
+ * sure that the result slot has a local copy of any pass-by-reference
+ * values.
+ */
+ if (context->cpDeletedSlot)
+ {
+ ExecMaterializeSlot(result);
+ ExecClearTuple(oldSlot);
+ if (context->cpDeletedSlot != oldSlot)
+ ExecClearTuple(context->cpDeletedSlot);
+ context->cpDeletedSlot = NULL;
+ }
+ }
if (inserted_tuple)
*inserted_tuple = slot;
Relation resultRelationDesc = resultRelInfo->ri_RelationDesc;
TupleTableSlot *slot = NULL;
TM_Result result;
+ bool saveOld;
if (tupleDeleted)
*tupleDeleted = false;
ExecDeleteEpilogue(context, resultRelInfo, tupleid, oldtuple, changingPart);
- /* Process RETURNING if present and if requested */
- if (processReturning && resultRelInfo->ri_projectReturning)
+ /*
+ * Process RETURNING if present and if requested.
+ *
+ * If this is part of a cross-partition UPDATE, and the RETURNING list
+ * refers to any OLD column values, save the old tuple here for later
+ * processing of the RETURNING list by ExecInsert().
+ */
+ saveOld = changingPart && resultRelInfo->ri_projectReturning &&
+ resultRelInfo->ri_projectReturning->pi_state.flags & EEO_FLAG_HAS_OLD;
+
+ if (resultRelInfo->ri_projectReturning && (processReturning || saveOld))
{
/*
* We have to put the target tuple into a slot, which means first we
}
}
- rslot = ExecProcessReturning(resultRelInfo, slot, context->planSlot);
+ /*
+ * If required, save the old tuple for later processing of the
+ * RETURNING list by ExecInsert().
+ */
+ if (saveOld)
+ {
+ TupleConversionMap *tupconv_map;
+
+ /*
+ * Convert the tuple into the root partition's format/slot, if
+ * needed. ExecInsert() will then convert it to the new
+ * partition's format/slot, if necessary.
+ */
+ tupconv_map = ExecGetChildToRootMap(resultRelInfo);
+ if (tupconv_map != NULL)
+ {
+ ResultRelInfo *rootRelInfo = context->mtstate->rootResultRelInfo;
+ TupleTableSlot *oldSlot = slot;
+
+ slot = execute_attr_map_slot(tupconv_map->attrMap,
+ slot,
+ ExecGetReturningSlot(estate,
+ rootRelInfo));
+
+ slot->tts_tableOid = oldSlot->tts_tableOid;
+ ItemPointerCopy(&oldSlot->tts_tid, &slot->tts_tid);
+ }
+
+ context->cpDeletedSlot = slot;
+
+ return NULL;
+ }
+
+ rslot = ExecProcessReturning(context, resultRelInfo, CMD_DELETE,
+ slot, NULL, context->planSlot);
/*
* Before releasing the target tuple again, make sure rslot has a
bool tuple_deleted;
TupleTableSlot *epqslot = NULL;
+ context->cpDeletedSlot = NULL;
context->cpUpdateReturningSlot = NULL;
*retry_slot = NULL;
* the planSlot. oldtuple is passed to foreign table triggers; it is
* NULL when the foreign table has no relevant triggers.
*
+ * oldSlot contains the old tuple value.
* slot contains the new tuple value to be stored.
* planSlot is the output of the ModifyTable's subplan; we use it
* to access values from other input tables (for RETURNING),
projects / users / c2main / postgres.git / commitdiff