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|
-- sanity check of system catalog
SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
attrelid | attname | attgenerated
----------+---------+--------------
(0 rows)
CREATE TABLE gtest0 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (55) STORED);
CREATE TABLE gtest1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
SELECT table_name, column_name, column_default, is_nullable, is_generated, generation_expression FROM information_schema.columns WHERE table_name LIKE 'gtest_' ORDER BY 1, 2;
table_name | column_name | column_default | is_nullable | is_generated | generation_expression
------------+-------------+----------------+-------------+--------------+-----------------------
gtest0 | a | | NO | NEVER |
gtest0 | b | | YES | ALWAYS | 55
gtest1 | a | | NO | NEVER |
gtest1 | b | | YES | ALWAYS | (a * 2)
(4 rows)
SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage ORDER BY 1, 2, 3;
table_name | column_name | dependent_column
------------+-------------+------------------
gtest1 | a | b
(1 row)
\d gtest1
Table "public.gtest1"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | not null |
b | integer | | | generated always as (a * 2) stored
Indexes:
"gtest1_pkey" PRIMARY KEY, btree (a)
-- duplicate generated
CREATE TABLE gtest_err_1 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ALWAYS AS (a * 3) STORED);
ERROR: multiple generation clauses specified for column "b" of table "gtest_err_1"
LINE 1: ...ARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED GENERATED ...
^
-- references to other generated columns, including self-references
CREATE TABLE gtest_err_2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STORED);
ERROR: cannot use generated column "b" in column generation expression
LINE 1: ...2a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (b * 2) STO...
^
DETAIL: A generated column cannot reference another generated column.
CREATE TABLE gtest_err_2b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STORED);
ERROR: cannot use generated column "b" in column generation expression
LINE 1: ...AYS AS (a * 2) STORED, c int GENERATED ALWAYS AS (b * 3) STO...
^
DETAIL: A generated column cannot reference another generated column.
-- a whole-row var is a self-reference on steroids, so disallow that too
CREATE TABLE gtest_err_2c (a int PRIMARY KEY,
b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STORED);
ERROR: cannot use whole-row variable in column generation expression
LINE 2: b int GENERATED ALWAYS AS (num_nulls(gtest_err_2c)) STOR...
^
DETAIL: This would cause the generated column to depend on its own value.
-- invalid reference
CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
ERROR: column "c" does not exist
LINE 1: ..._3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STO...
^
-- generation expression must be immutable
CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) STORED);
ERROR: generation expression is not immutable
-- cannot have default/identity and generated
CREATE TABLE gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ALWAYS AS (a * 2) STORED);
ERROR: both default and generation expression specified for column "b" of table "gtest_err_5a"
LINE 1: ... gtest_err_5a (a int PRIMARY KEY, b int DEFAULT 5 GENERATED ...
^
CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) STORED);
ERROR: both identity and generation expression specified for column "b" of table "gtest_err_5b"
LINE 1: ...t PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ...
^
-- reference to system column not allowed in generated column
-- (except tableoid, which we test below)
CREATE TABLE gtest_err_6a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37) STORED);
ERROR: cannot use system column "xmin" in column generation expression
LINE 1: ...a (a int PRIMARY KEY, b bool GENERATED ALWAYS AS (xmin <> 37...
^
-- various prohibited constructs
CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) STORED);
ERROR: aggregate functions are not allowed in column generation expressions
LINE 1: ...7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) ST...
^
CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) STORED);
ERROR: window functions are not allowed in column generation expressions
LINE 1: ...7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number...
^
CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) STORED);
ERROR: cannot use subquery in column generation expression
LINE 1: ...7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)...
^
CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) STORED);
ERROR: set-returning functions are not allowed in column generation expressions
LINE 1: ...7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_s...
^
-- GENERATED BY DEFAULT not allowed
CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
ERROR: for a generated column, GENERATED ALWAYS must be specified
LINE 1: ...E gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT...
^
INSERT INTO gtest1 VALUES (1);
INSERT INTO gtest1 VALUES (2, DEFAULT);
INSERT INTO gtest1 VALUES (3, 33); -- error
ERROR: cannot insert into column "b"
DETAIL: Column "b" is a generated column.
SELECT * FROM gtest1 ORDER BY a;
a | b
---+---
1 | 2
2 | 4
(2 rows)
UPDATE gtest1 SET b = DEFAULT WHERE a = 1;
UPDATE gtest1 SET b = 11 WHERE a = 1; -- error
ERROR: column "b" can only be updated to DEFAULT
DETAIL: Column "b" is a generated column.
SELECT * FROM gtest1 ORDER BY a;
a | b
---+---
1 | 2
2 | 4
(2 rows)
SELECT a, b, b * 2 AS b2 FROM gtest1 ORDER BY a;
a | b | b2
---+---+----
1 | 2 | 4
2 | 4 | 8
(2 rows)
SELECT a, b FROM gtest1 WHERE b = 4 ORDER BY a;
a | b
---+---
2 | 4
(1 row)
-- test that overflow error happens on write
INSERT INTO gtest1 VALUES (2000000000);
ERROR: integer out of range
SELECT * FROM gtest1;
a | b
---+---
2 | 4
1 | 2
(2 rows)
DELETE FROM gtest1 WHERE a = 2000000000;
-- test with joins
CREATE TABLE gtestx (x int, y int);
INSERT INTO gtestx VALUES (11, 1), (22, 2), (33, 3);
SELECT * FROM gtestx, gtest1 WHERE gtestx.y = gtest1.a;
x | y | a | b
----+---+---+---
11 | 1 | 1 | 2
22 | 2 | 2 | 4
(2 rows)
DROP TABLE gtestx;
-- test UPDATE/DELETE quals
SELECT * FROM gtest1 ORDER BY a;
a | b
---+---
1 | 2
2 | 4
(2 rows)
UPDATE gtest1 SET a = 3 WHERE b = 4;
SELECT * FROM gtest1 ORDER BY a;
a | b
---+---
1 | 2
3 | 6
(2 rows)
DELETE FROM gtest1 WHERE b = 2;
SELECT * FROM gtest1 ORDER BY a;
a | b
---+---
3 | 6
(1 row)
-- views
CREATE VIEW gtest1v AS SELECT * FROM gtest1;
SELECT * FROM gtest1v;
a | b
---+---
3 | 6
(1 row)
INSERT INTO gtest1v VALUES (4, 8); -- fails
ERROR: cannot insert into column "b"
DETAIL: Column "b" is a generated column.
DROP VIEW gtest1v;
-- CTEs
WITH foo AS (SELECT * FROM gtest1) SELECT * FROM foo;
a | b
---+---
3 | 6
(1 row)
-- inheritance
CREATE TABLE gtest1_1 () INHERITS (gtest1);
SELECT * FROM gtest1_1;
a | b
---+---
(0 rows)
\d gtest1_1
Table "public.gtest1_1"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | not null |
b | integer | | | generated always as (a * 2) stored
Inherits: gtest1
INSERT INTO gtest1_1 VALUES (4);
SELECT * FROM gtest1_1;
a | b
---+---
4 | 8
(1 row)
SELECT * FROM gtest1;
a | b
---+---
3 | 6
4 | 8
(2 rows)
CREATE TABLE gtest_normal (a int, b int);
CREATE TABLE gtest_normal_child (a int, b int GENERATED ALWAYS AS (a * 2) STORED) INHERITS (gtest_normal);
NOTICE: merging column "a" with inherited definition
NOTICE: merging column "b" with inherited definition
\d gtest_normal_child
Table "public.gtest_normal_child"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | |
b | integer | | | generated always as (a * 2) stored
Inherits: gtest_normal
INSERT INTO gtest_normal (a) VALUES (1);
INSERT INTO gtest_normal_child (a) VALUES (2);
SELECT * FROM gtest_normal;
a | b
---+---
1 |
2 | 4
(2 rows)
CREATE TABLE gtest_normal_child2 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
ALTER TABLE gtest_normal_child2 INHERIT gtest_normal;
INSERT INTO gtest_normal_child2 (a) VALUES (3);
SELECT * FROM gtest_normal;
a | b
---+---
1 |
2 | 4
3 | 9
(3 rows)
-- test inheritance mismatches between parent and child
CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1); -- error
NOTICE: merging column "b" with inherited definition
ERROR: child column "b" specifies generation expression
HINT: Omit the generation expression in the definition of the child table column to inherit the generation expression from the parent table.
CREATE TABLE gtestx (x int, b int DEFAULT 10) INHERITS (gtest1); -- error
NOTICE: merging column "b" with inherited definition
ERROR: column "b" inherits from generated column but specifies default
CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS IDENTITY) INHERITS (gtest1); -- error
NOTICE: merging column "b" with inherited definition
ERROR: column "b" inherits from generated column but specifies identity
CREATE TABLE gtestxx_1 (a int NOT NULL, b int);
ALTER TABLE gtestxx_1 INHERIT gtest1; -- error
ERROR: column "b" in child table must be a generated column
CREATE TABLE gtestxx_2 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 22) STORED);
ALTER TABLE gtestxx_2 INHERIT gtest1; -- error
ERROR: column "b" in child table has a conflicting generation expression
CREATE TABLE gtestxx_3 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 2) STORED);
ALTER TABLE gtestxx_3 INHERIT gtest1; -- ok
CREATE TABLE gtestxx_4 (b int GENERATED ALWAYS AS (a * 2) STORED, a int NOT NULL);
ALTER TABLE gtestxx_4 INHERIT gtest1; -- ok
-- test multiple inheritance mismatches
CREATE TABLE gtesty (x int, b int);
CREATE TABLE gtest1_2 () INHERITS (gtest1, gtesty); -- error
NOTICE: merging multiple inherited definitions of column "b"
ERROR: inherited column "b" has a generation conflict
DROP TABLE gtesty;
CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) STORED);
CREATE TABLE gtest1_2 () INHERITS (gtest1, gtesty); -- error
NOTICE: merging multiple inherited definitions of column "b"
ERROR: column "b" inherits conflicting generation expressions
DROP TABLE gtesty;
CREATE TABLE gtesty (x int, b int DEFAULT 55);
CREATE TABLE gtest1_2 () INHERITS (gtest0, gtesty); -- error
NOTICE: merging multiple inherited definitions of column "b"
ERROR: inherited column "b" has a generation conflict
DROP TABLE gtesty;
-- test stored update
CREATE TABLE gtest3 (a int, b int GENERATED ALWAYS AS (a * 3) STORED);
INSERT INTO gtest3 (a) VALUES (1), (2), (3), (NULL);
SELECT * FROM gtest3 ORDER BY a;
a | b
---+---
1 | 3
2 | 6
3 | 9
|
(4 rows)
UPDATE gtest3 SET a = 22 WHERE a = 2;
SELECT * FROM gtest3 ORDER BY a;
a | b
----+----
1 | 3
3 | 9
22 | 66
|
(4 rows)
CREATE TABLE gtest3a (a text, b text GENERATED ALWAYS AS (a || '+' || a) STORED);
INSERT INTO gtest3a (a) VALUES ('a'), ('b'), ('c'), (NULL);
SELECT * FROM gtest3a ORDER BY a;
a | b
---+-----
a | a+a
b | b+b
c | c+c
|
(4 rows)
UPDATE gtest3a SET a = 'bb' WHERE a = 'b';
SELECT * FROM gtest3a ORDER BY a;
a | b
----+-------
a | a+a
bb | bb+bb
c | c+c
|
(4 rows)
-- COPY
TRUNCATE gtest1;
INSERT INTO gtest1 (a) VALUES (1), (2);
COPY gtest1 TO stdout;
1
2
COPY gtest1 (a, b) TO stdout;
ERROR: column "b" is a generated column
DETAIL: Generated columns cannot be used in COPY.
COPY gtest1 FROM stdin;
COPY gtest1 (a, b) FROM stdin;
ERROR: column "b" is a generated column
DETAIL: Generated columns cannot be used in COPY.
SELECT * FROM gtest1 ORDER BY a;
a | b
---+---
1 | 2
2 | 4
3 | 6
4 | 8
(4 rows)
TRUNCATE gtest3;
INSERT INTO gtest3 (a) VALUES (1), (2);
COPY gtest3 TO stdout;
1
2
COPY gtest3 (a, b) TO stdout;
ERROR: column "b" is a generated column
DETAIL: Generated columns cannot be used in COPY.
COPY gtest3 FROM stdin;
COPY gtest3 (a, b) FROM stdin;
ERROR: column "b" is a generated column
DETAIL: Generated columns cannot be used in COPY.
SELECT * FROM gtest3 ORDER BY a;
a | b
---+----
1 | 3
2 | 6
3 | 9
4 | 12
(4 rows)
-- null values
CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) STORED);
INSERT INTO gtest2 VALUES (1);
SELECT * FROM gtest2;
a | b
---+---
1 |
(1 row)
-- simple column reference for varlena types
CREATE TABLE gtest_varlena (a varchar, b varchar GENERATED ALWAYS AS (a) STORED);
INSERT INTO gtest_varlena (a) VALUES('01234567890123456789');
INSERT INTO gtest_varlena (a) VALUES(NULL);
SELECT * FROM gtest_varlena ORDER BY a;
a | b
----------------------+----------------------
01234567890123456789 | 01234567890123456789
|
(2 rows)
DROP TABLE gtest_varlena;
-- composite types
CREATE TYPE double_int as (a int, b int);
CREATE TABLE gtest4 (
a int,
b double_int GENERATED ALWAYS AS ((a * 2, a * 3)) STORED
);
INSERT INTO gtest4 VALUES (1), (6);
SELECT * FROM gtest4;
a | b
---+---------
1 | (2,3)
6 | (12,18)
(2 rows)
DROP TABLE gtest4;
DROP TYPE double_int;
-- using tableoid is allowed
CREATE TABLE gtest_tableoid (
a int PRIMARY KEY,
b bool GENERATED ALWAYS AS (tableoid = 'gtest_tableoid'::regclass) STORED
);
INSERT INTO gtest_tableoid VALUES (1), (2);
ALTER TABLE gtest_tableoid ADD COLUMN
c regclass GENERATED ALWAYS AS (tableoid) STORED;
SELECT * FROM gtest_tableoid;
a | b | c
---+---+----------------
1 | t | gtest_tableoid
2 | t | gtest_tableoid
(2 rows)
-- drop column behavior
CREATE TABLE gtest10 (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
ALTER TABLE gtest10 DROP COLUMN b;
\d gtest10
Table "public.gtest10"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
a | integer | | not null |
Indexes:
"gtest10_pkey" PRIMARY KEY, btree (a)
CREATE TABLE gtest10a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
ALTER TABLE gtest10a DROP COLUMN b;
INSERT INTO gtest10a (a) VALUES (1);
-- privileges
CREATE USER regress_user11;
CREATE TABLE gtest11s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (b * 2) STORED);
INSERT INTO gtest11s VALUES (1, 10), (2, 20);
GRANT SELECT (a, c) ON gtest11s TO regress_user11;
CREATE FUNCTION gf1(a int) RETURNS int AS $$ SELECT a * 3 $$ IMMUTABLE LANGUAGE SQL;
REVOKE ALL ON FUNCTION gf1(int) FROM PUBLIC;
CREATE TABLE gtest12s (a int PRIMARY KEY, b int, c int GENERATED ALWAYS AS (gf1(b)) STORED);
INSERT INTO gtest12s VALUES (1, 10), (2, 20);
GRANT SELECT (a, c) ON gtest12s TO regress_user11;
SET ROLE regress_user11;
SELECT a, b FROM gtest11s; -- not allowed
ERROR: permission denied for table gtest11s
SELECT a, c FROM gtest11s; -- allowed
a | c
---+----
1 | 20
2 | 40
(2 rows)
SELECT gf1(10); -- not allowed
ERROR: permission denied for function gf1
SELECT a, c FROM gtest12s; -- allowed
a | c
---+----
1 | 30
2 | 60
(2 rows)
RESET ROLE;
DROP TABLE gtest11s, gtest12s;
DROP FUNCTION gf1(int);
DROP USER regress_user11;
-- check constraints
CREATE TABLE gtest20 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED CHECK (b < 50));
INSERT INTO gtest20 (a) VALUES (10); -- ok
INSERT INTO gtest20 (a) VALUES (30); -- violates constraint
ERROR: new row for relation "gtest20" violates check constraint "gtest20_b_check"
DETAIL: Failing row contains (30, 60).
CREATE TABLE gtest20a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
INSERT INTO gtest20a (a) VALUES (10);
INSERT INTO gtest20a (a) VALUES (30);
ALTER TABLE gtest20a ADD CHECK (b < 50); -- fails on existing row
ERROR: check constraint "gtest20a_b_check" of relation "gtest20a" is violated by some row
CREATE TABLE gtest20b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED);
INSERT INTO gtest20b (a) VALUES (10);
INSERT INTO gtest20b (a) VALUES (30);
ALTER TABLE gtest20b ADD CONSTRAINT chk CHECK (b < 50) NOT VALID;
ALTER TABLE gtest20b VALIDATE CONSTRAINT chk; -- fails on existing row
ERROR: check constraint "chk" of relation "gtest20b" is violated by some row
-- not-null constraints
CREATE TABLE gtest21a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED NOT NULL);
INSERT INTO gtest21a (a) VALUES (1); -- ok
INSERT INTO gtest21a (a) VALUES (0); -- violates constraint
ERROR: null value in column "b" of relation "gtest21a" violates not-null constraint
DETAIL: Failing row contains (0, null).
CREATE TABLE gtest21b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (nullif(a, 0)) STORED);
ALTER TABLE gtest21b ALTER COLUMN b SET NOT NULL;
INSERT INTO gtest21b (a) VALUES (1); -- ok
INSERT INTO gtest21b (a) VALUES (0); -- violates constraint
ERROR: null value in column "b" of relation "gtest21b" violates not-null constraint
DETAIL: Failing row contains (0, null).
ALTER TABLE gtest21b ALTER COLUMN b DROP NOT NULL;
INSERT INTO gtest21b (a) VALUES (0); -- ok now
-- index constraints
CREATE TABLE gtest22a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a / 2) STORED UNIQUE);
INSERT INTO gtest22a VALUES (2);
INSERT INTO gtest22a VALUES (3);
ERROR: duplicate key value violates unique constraint "gtest22a_b_key"
DETAIL: Key (b)=(1) already exists.
INSERT INTO gtest22a VALUES (4);
CREATE TABLE gtest22b (a int, b int GENERATED ALWAYS AS (a / 2) STORED, PRIMARY KEY (a, b));
INSERT INTO gtest22b VALUES (2);
INSERT INTO gtest22b VALUES (2);
ERROR: duplicate key value violates unique constraint "gtest22b_pkey"
DETAIL: Key (a, b)=(2, 1) already exists.
-- indexes
CREATE TABLE gtest22c (a int, b int GENERATED ALWAYS AS (a * 2) STORED);
CREATE INDEX gtest22c_b_idx ON gtest22c (b);
CREATE INDEX gtest22c_expr_idx ON gtest22c ((b * 3));
CREATE INDEX gtest22c_pred_idx ON gtest22c (a) WHERE b > 0;
\d gtest22c
Table "public.gtest22c"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | |
b | integer | | | generated always as (a * 2) stored
Indexes:
"gtest22c_b_idx" btree (b)
"gtest22c_expr_idx" btree ((b * 3))
"gtest22c_pred_idx" btree (a) WHERE b > 0
INSERT INTO gtest22c VALUES (1), (2), (3);
SET enable_seqscan TO off;
SET enable_bitmapscan TO off;
EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b = 4;
QUERY PLAN
---------------------------------------------
Index Scan using gtest22c_b_idx on gtest22c
Index Cond: (b = 4)
(2 rows)
SELECT * FROM gtest22c WHERE b = 4;
a | b
---+---
2 | 4
(1 row)
EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
QUERY PLAN
------------------------------------------------
Index Scan using gtest22c_expr_idx on gtest22c
Index Cond: ((b * 3) = 6)
(2 rows)
SELECT * FROM gtest22c WHERE b * 3 = 6;
a | b
---+---
1 | 2
(1 row)
EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
QUERY PLAN
------------------------------------------------
Index Scan using gtest22c_pred_idx on gtest22c
Index Cond: (a = 1)
(2 rows)
SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
a | b
---+---
1 | 2
(1 row)
RESET enable_seqscan;
RESET enable_bitmapscan;
-- foreign keys
CREATE TABLE gtest23a (x int PRIMARY KEY, y int);
INSERT INTO gtest23a VALUES (1, 11), (2, 22), (3, 33);
CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON UPDATE CASCADE); -- error
ERROR: invalid ON UPDATE action for foreign key constraint containing generated column
CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON DELETE SET NULL); -- error
ERROR: invalid ON DELETE action for foreign key constraint containing generated column
CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
\d gtest23b
Table "public.gtest23b"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | not null |
b | integer | | | generated always as (a * 2) stored
Indexes:
"gtest23b_pkey" PRIMARY KEY, btree (a)
Foreign-key constraints:
"gtest23b_b_fkey" FOREIGN KEY (b) REFERENCES gtest23a(x)
INSERT INTO gtest23b VALUES (1); -- ok
INSERT INTO gtest23b VALUES (5); -- error
ERROR: insert or update on table "gtest23b" violates foreign key constraint "gtest23b_b_fkey"
DETAIL: Key (b)=(10) is not present in table "gtest23a".
DROP TABLE gtest23b;
DROP TABLE gtest23a;
CREATE TABLE gtest23p (x int, y int GENERATED ALWAYS AS (x * 2) STORED, PRIMARY KEY (y));
INSERT INTO gtest23p VALUES (1), (2), (3);
CREATE TABLE gtest23q (a int PRIMARY KEY, b int REFERENCES gtest23p (y));
INSERT INTO gtest23q VALUES (1, 2); -- ok
INSERT INTO gtest23q VALUES (2, 5); -- error
ERROR: insert or update on table "gtest23q" violates foreign key constraint "gtest23q_b_fkey"
DETAIL: Key (b)=(5) is not present in table "gtest23p".
-- domains
CREATE DOMAIN gtestdomain1 AS int CHECK (VALUE < 10);
CREATE TABLE gtest24 (a int PRIMARY KEY, b gtestdomain1 GENERATED ALWAYS AS (a * 2) STORED);
INSERT INTO gtest24 (a) VALUES (4); -- ok
INSERT INTO gtest24 (a) VALUES (6); -- error
ERROR: value for domain gtestdomain1 violates check constraint "gtestdomain1_check"
-- typed tables (currently not supported)
CREATE TYPE gtest_type AS (f1 integer, f2 text, f3 bigint);
CREATE TABLE gtest28 OF gtest_type (f1 WITH OPTIONS GENERATED ALWAYS AS (f2 *2) STORED);
ERROR: generated columns are not supported on typed tables
DROP TYPE gtest_type CASCADE;
-- table partitions (currently not supported)
CREATE TABLE gtest_parent (f1 date NOT NULL, f2 text, f3 bigint) PARTITION BY RANGE (f1);
CREATE TABLE gtest_child PARTITION OF gtest_parent (
f3 WITH OPTIONS GENERATED ALWAYS AS (f2 * 2) STORED
) FOR VALUES FROM ('2016-07-01') TO ('2016-08-01'); -- error
ERROR: generated columns are not supported on partitions
DROP TABLE gtest_parent;
-- partitioned table
CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f1);
CREATE TABLE gtest_child PARTITION OF gtest_parent FOR VALUES FROM ('2016-07-01') TO ('2016-08-01');
INSERT INTO gtest_parent (f1, f2) VALUES ('2016-07-15', 1);
SELECT * FROM gtest_parent;
f1 | f2 | f3
------------+----+----
07-15-2016 | 1 | 2
(1 row)
SELECT * FROM gtest_child;
f1 | f2 | f3
------------+----+----
07-15-2016 | 1 | 2
(1 row)
DROP TABLE gtest_parent;
-- generated columns in partition key (not allowed)
CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
ERROR: cannot use generated column in partition key
LINE 1: ...ENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE (f3);
^
DETAIL: Column "f3" is a generated column.
CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
ERROR: cannot use generated column in partition key
LINE 1: ...ED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
^
DETAIL: Column "f3" is a generated column.
-- ALTER TABLE ... ADD COLUMN
CREATE TABLE gtest25 (a int PRIMARY KEY);
INSERT INTO gtest25 VALUES (3), (4);
ALTER TABLE gtest25 ADD COLUMN b int GENERATED ALWAYS AS (a * 3) STORED;
SELECT * FROM gtest25 ORDER BY a;
a | b
---+----
3 | 9
4 | 12
(2 rows)
ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) STORED; -- error
ERROR: cannot use generated column "b" in column generation expression
DETAIL: A generated column cannot reference another generated column.
ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) STORED; -- error
ERROR: column "z" does not exist
ALTER TABLE gtest25 ADD COLUMN c int DEFAULT 42,
ADD COLUMN x int GENERATED ALWAYS AS (c * 4) STORED;
ALTER TABLE gtest25 ADD COLUMN d int DEFAULT 101;
ALTER TABLE gtest25 ALTER COLUMN d SET DATA TYPE float8,
ADD COLUMN y float8 GENERATED ALWAYS AS (d * 4) STORED;
SELECT * FROM gtest25 ORDER BY a;
a | b | c | x | d | y
---+----+----+-----+-----+-----
3 | 9 | 42 | 168 | 101 | 404
4 | 12 | 42 | 168 | 101 | 404
(2 rows)
\d gtest25
Table "public.gtest25"
Column | Type | Collation | Nullable | Default
--------+------------------+-----------+----------+------------------------------------------------------
a | integer | | not null |
b | integer | | | generated always as (a * 3) stored
c | integer | | | 42
x | integer | | | generated always as (c * 4) stored
d | double precision | | | 101
y | double precision | | | generated always as (d * 4::double precision) stored
Indexes:
"gtest25_pkey" PRIMARY KEY, btree (a)
-- ALTER TABLE ... ALTER COLUMN
CREATE TABLE gtest27 (
a int,
b int,
x int GENERATED ALWAYS AS ((a + b) * 2) STORED
);
INSERT INTO gtest27 (a, b) VALUES (3, 7), (4, 11);
ALTER TABLE gtest27 ALTER COLUMN a TYPE text; -- error
ERROR: cannot alter type of a column used by a generated column
DETAIL: Column "a" is used by generated column "x".
ALTER TABLE gtest27 ALTER COLUMN x TYPE numeric;
\d gtest27
Table "public.gtest27"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+--------------------------------------------
a | integer | | |
b | integer | | |
x | numeric | | | generated always as (((a + b) * 2)) stored
SELECT * FROM gtest27;
a | b | x
---+----+----
3 | 7 | 20
4 | 11 | 30
(2 rows)
ALTER TABLE gtest27 ALTER COLUMN x TYPE boolean USING x <> 0; -- error
ERROR: generation expression for column "x" cannot be cast automatically to type boolean
ALTER TABLE gtest27 ALTER COLUMN x DROP DEFAULT; -- error
ERROR: column "x" of relation "gtest27" is a generated column
HINT: Use ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION instead.
-- It's possible to alter the column types this way:
ALTER TABLE gtest27
DROP COLUMN x,
ALTER COLUMN a TYPE bigint,
ALTER COLUMN b TYPE bigint,
ADD COLUMN x bigint GENERATED ALWAYS AS ((a + b) * 2) STORED;
\d gtest27
Table "public.gtest27"
Column | Type | Collation | Nullable | Default
--------+--------+-----------+----------+------------------------------------------
a | bigint | | |
b | bigint | | |
x | bigint | | | generated always as ((a + b) * 2) stored
-- Ideally you could just do this, but not today (and should x change type?):
ALTER TABLE gtest27
ALTER COLUMN a TYPE float8,
ALTER COLUMN b TYPE float8; -- error
ERROR: cannot alter type of a column used by a generated column
DETAIL: Column "a" is used by generated column "x".
\d gtest27
Table "public.gtest27"
Column | Type | Collation | Nullable | Default
--------+--------+-----------+----------+------------------------------------------
a | bigint | | |
b | bigint | | |
x | bigint | | | generated always as ((a + b) * 2) stored
SELECT * FROM gtest27;
a | b | x
---+----+----
3 | 7 | 20
4 | 11 | 30
(2 rows)
-- ALTER TABLE ... ALTER COLUMN ... DROP EXPRESSION
CREATE TABLE gtest29 (
a int,
b int GENERATED ALWAYS AS (a * 2) STORED
);
INSERT INTO gtest29 (a) VALUES (3), (4);
ALTER TABLE gtest29 ALTER COLUMN a DROP EXPRESSION; -- error
ERROR: column "a" of relation "gtest29" is not a stored generated column
ALTER TABLE gtest29 ALTER COLUMN a DROP EXPRESSION IF EXISTS; -- notice
NOTICE: column "a" of relation "gtest29" is not a stored generated column, skipping
ALTER TABLE gtest29 ALTER COLUMN b DROP EXPRESSION;
INSERT INTO gtest29 (a) VALUES (5);
INSERT INTO gtest29 (a, b) VALUES (6, 66);
SELECT * FROM gtest29;
a | b
---+----
3 | 6
4 | 8
5 |
6 | 66
(4 rows)
\d gtest29
Table "public.gtest29"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
a | integer | | |
b | integer | | |
-- check that dependencies between columns have also been removed
ALTER TABLE gtest29 DROP COLUMN a; -- should not drop b
\d gtest29
Table "public.gtest29"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
b | integer | | |
-- with inheritance
CREATE TABLE gtest30 (
a int,
b int GENERATED ALWAYS AS (a * 2) STORED
);
CREATE TABLE gtest30_1 () INHERITS (gtest30);
ALTER TABLE gtest30 ALTER COLUMN b DROP EXPRESSION;
\d gtest30
Table "public.gtest30"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
a | integer | | |
b | integer | | |
Number of child tables: 1 (Use \d+ to list them.)
\d gtest30_1
Table "public.gtest30_1"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+---------
a | integer | | |
b | integer | | |
Inherits: gtest30
DROP TABLE gtest30 CASCADE;
NOTICE: drop cascades to table gtest30_1
CREATE TABLE gtest30 (
a int,
b int GENERATED ALWAYS AS (a * 2) STORED
);
CREATE TABLE gtest30_1 () INHERITS (gtest30);
ALTER TABLE ONLY gtest30 ALTER COLUMN b DROP EXPRESSION; -- error
ERROR: ALTER TABLE / DROP EXPRESSION must be applied to child tables too
\d gtest30
Table "public.gtest30"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | |
b | integer | | | generated always as (a * 2) stored
Number of child tables: 1 (Use \d+ to list them.)
\d gtest30_1
Table "public.gtest30_1"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
a | integer | | |
b | integer | | | generated always as (a * 2) stored
Inherits: gtest30
ALTER TABLE gtest30_1 ALTER COLUMN b DROP EXPRESSION; -- error
ERROR: cannot drop generation expression from inherited column
-- triggers
CREATE TABLE gtest26 (
a int PRIMARY KEY,
b int GENERATED ALWAYS AS (a * 2) STORED
);
CREATE FUNCTION gtest_trigger_func() RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
IF tg_op IN ('DELETE', 'UPDATE') THEN
RAISE INFO '%: %: old = %', TG_NAME, TG_WHEN, OLD;
END IF;
IF tg_op IN ('INSERT', 'UPDATE') THEN
RAISE INFO '%: %: new = %', TG_NAME, TG_WHEN, NEW;
END IF;
IF tg_op = 'DELETE' THEN
RETURN OLD;
ELSE
RETURN NEW;
END IF;
END
$$;
CREATE TRIGGER gtest1 BEFORE DELETE OR UPDATE ON gtest26
FOR EACH ROW
WHEN (OLD.b < 0) -- ok
EXECUTE PROCEDURE gtest_trigger_func();
CREATE TRIGGER gtest2a BEFORE INSERT OR UPDATE ON gtest26
FOR EACH ROW
WHEN (NEW.b < 0) -- error
EXECUTE PROCEDURE gtest_trigger_func();
ERROR: BEFORE trigger's WHEN condition cannot reference NEW generated columns
LINE 3: WHEN (NEW.b < 0)
^
DETAIL: Column "b" is a generated column.
CREATE TRIGGER gtest2b BEFORE INSERT OR UPDATE ON gtest26
FOR EACH ROW
WHEN (NEW.* IS NOT NULL) -- error
EXECUTE PROCEDURE gtest_trigger_func();
ERROR: BEFORE trigger's WHEN condition cannot reference NEW generated columns
LINE 3: WHEN (NEW.* IS NOT NULL)
^
DETAIL: A whole-row reference is used and the table contains generated columns.
CREATE TRIGGER gtest2 BEFORE INSERT ON gtest26
FOR EACH ROW
WHEN (NEW.a < 0)
EXECUTE PROCEDURE gtest_trigger_func();
CREATE TRIGGER gtest3 AFTER DELETE OR UPDATE ON gtest26
FOR EACH ROW
WHEN (OLD.b < 0) -- ok
EXECUTE PROCEDURE gtest_trigger_func();
CREATE TRIGGER gtest4 AFTER INSERT OR UPDATE ON gtest26
FOR EACH ROW
WHEN (NEW.b < 0) -- ok
EXECUTE PROCEDURE gtest_trigger_func();
INSERT INTO gtest26 (a) VALUES (-2), (0), (3);
INFO: gtest2: BEFORE: new = (-2,)
INFO: gtest4: AFTER: new = (-2,-4)
SELECT * FROM gtest26 ORDER BY a;
a | b
----+----
-2 | -4
0 | 0
3 | 6
(3 rows)
UPDATE gtest26 SET a = a * -2;
INFO: gtest1: BEFORE: old = (-2,-4)
INFO: gtest1: BEFORE: new = (4,)
INFO: gtest3: AFTER: old = (-2,-4)
INFO: gtest3: AFTER: new = (4,8)
INFO: gtest4: AFTER: old = (3,6)
INFO: gtest4: AFTER: new = (-6,-12)
SELECT * FROM gtest26 ORDER BY a;
a | b
----+-----
-6 | -12
0 | 0
4 | 8
(3 rows)
DELETE FROM gtest26 WHERE a = -6;
INFO: gtest1: BEFORE: old = (-6,-12)
INFO: gtest3: AFTER: old = (-6,-12)
SELECT * FROM gtest26 ORDER BY a;
a | b
---+---
0 | 0
4 | 8
(2 rows)
DROP TRIGGER gtest1 ON gtest26;
DROP TRIGGER gtest2 ON gtest26;
DROP TRIGGER gtest3 ON gtest26;
-- Check that an UPDATE of "a" fires the trigger for UPDATE OF b, per
-- SQL standard.
CREATE FUNCTION gtest_trigger_func3() RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
RAISE NOTICE 'OK';
RETURN NEW;
END
$$;
CREATE TRIGGER gtest11 BEFORE UPDATE OF b ON gtest26
FOR EACH ROW
EXECUTE PROCEDURE gtest_trigger_func3();
UPDATE gtest26 SET a = 1 WHERE a = 0;
NOTICE: OK
DROP TRIGGER gtest11 ON gtest26;
TRUNCATE gtest26;
-- check that modifications of stored generated columns in triggers do
-- not get propagated
CREATE FUNCTION gtest_trigger_func4() RETURNS trigger
LANGUAGE plpgsql
AS $$
BEGIN
NEW.a = 10;
NEW.b = 300;
RETURN NEW;
END;
$$;
CREATE TRIGGER gtest12_01 BEFORE UPDATE ON gtest26
FOR EACH ROW
EXECUTE PROCEDURE gtest_trigger_func();
CREATE TRIGGER gtest12_02 BEFORE UPDATE ON gtest26
FOR EACH ROW
EXECUTE PROCEDURE gtest_trigger_func4();
CREATE TRIGGER gtest12_03 BEFORE UPDATE ON gtest26
FOR EACH ROW
EXECUTE PROCEDURE gtest_trigger_func();
INSERT INTO gtest26 (a) VALUES (1);
UPDATE gtest26 SET a = 11 WHERE a = 1;
INFO: gtest12_01: BEFORE: old = (1,2)
INFO: gtest12_01: BEFORE: new = (11,)
INFO: gtest12_03: BEFORE: old = (1,2)
INFO: gtest12_03: BEFORE: new = (10,)
SELECT * FROM gtest26 ORDER BY a;
a | b
----+----
10 | 20
(1 row)
-- LIKE INCLUDING GENERATED and dropped column handling
CREATE TABLE gtest28a (
a int,
b int,
c int,
x int GENERATED ALWAYS AS (b * 2) STORED
);
ALTER TABLE gtest28a DROP COLUMN a;
CREATE TABLE gtest28b (LIKE gtest28a INCLUDING GENERATED);
\d gtest28*
Table "public.gtest28a"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
b | integer | | |
c | integer | | |
x | integer | | | generated always as (b * 2) stored
Table "public.gtest28b"
Column | Type | Collation | Nullable | Default
--------+---------+-----------+----------+------------------------------------
b | integer | | |
c | integer | | |
x | integer | | | generated always as (b * 2) stored
|