1 files changed, 611 insertions, 0 deletions
diff --git a/src/test/regress/sql/generated.sql b/src/test/regress/sql/generated.sql
new file mode 100644
index 0000000..8d25161
--- /dev/null
+++ b/src/test/regress/sql/generated.sql
@@ -0,0 +1,611 @@
+-- sanity check of system catalog
+SELECT attrelid, attname, attgenerated FROM pg_attribute WHERE attgenerated NOT IN ('', 's');
+
+
+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;
+
+SELECT table_name, column_name, dependent_column FROM information_schema.column_column_usage ORDER BY 1, 2, 3;
+
+\d gtest1
+
+-- 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);
+
+-- 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);
+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);
+-- 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);
+
+-- invalid reference
+CREATE TABLE gtest_err_3 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (c * 2) STORED);
+
+-- generation expression must be immutable
+CREATE TABLE gtest_err_4 (a int PRIMARY KEY, b double precision GENERATED ALWAYS AS (random()) STORED);
+
+-- 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);
+CREATE TABLE gtest_err_5b (a int PRIMARY KEY, b int GENERATED ALWAYS AS identity GENERATED ALWAYS AS (a * 2) STORED);
+
+-- 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);
+
+-- various prohibited constructs
+CREATE TABLE gtest_err_7a (a int PRIMARY KEY, b int GENERATED ALWAYS AS (avg(a)) STORED);
+CREATE TABLE gtest_err_7b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (row_number() OVER (ORDER BY a)) STORED);
+CREATE TABLE gtest_err_7c (a int PRIMARY KEY, b int GENERATED ALWAYS AS ((SELECT a)) STORED);
+CREATE TABLE gtest_err_7d (a int PRIMARY KEY, b int GENERATED ALWAYS AS (generate_series(1, a)) STORED);
+
+-- GENERATED BY DEFAULT not allowed
+CREATE TABLE gtest_err_8 (a int PRIMARY KEY, b int GENERATED BY DEFAULT AS (a * 2) STORED);
+
+INSERT INTO gtest1 VALUES (1);
+INSERT INTO gtest1 VALUES (2, DEFAULT);  -- ok
+INSERT INTO gtest1 VALUES (3, 33);  -- error
+INSERT INTO gtest1 VALUES (3, 33), (4, 44);  -- error
+INSERT INTO gtest1 VALUES (3, DEFAULT), (4, 44);  -- error
+INSERT INTO gtest1 VALUES (3, 33), (4, DEFAULT);  -- error
+INSERT INTO gtest1 VALUES (3, DEFAULT), (4, DEFAULT);  -- ok
+
+SELECT * FROM gtest1 ORDER BY a;
+DELETE FROM gtest1 WHERE a >= 3;
+
+UPDATE gtest1 SET b = DEFAULT WHERE a = 1;
+UPDATE gtest1 SET b = 11 WHERE a = 1;  -- error
+
+SELECT * FROM gtest1 ORDER BY a;
+
+SELECT a, b, b * 2 AS b2 FROM gtest1 ORDER BY a;
+SELECT a, b FROM gtest1 WHERE b = 4 ORDER BY a;
+
+-- test that overflow error happens on write
+INSERT INTO gtest1 VALUES (2000000000);
+SELECT * FROM gtest1;
+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;
+DROP TABLE gtestx;
+
+-- test UPDATE/DELETE quals
+SELECT * FROM gtest1 ORDER BY a;
+UPDATE gtest1 SET a = 3 WHERE b = 4;
+SELECT * FROM gtest1 ORDER BY a;
+DELETE FROM gtest1 WHERE b = 2;
+SELECT * FROM gtest1 ORDER BY a;
+
+-- test MERGE
+CREATE TABLE gtestm (
+  id int PRIMARY KEY,
+  f1 int,
+  f2 int,
+  f3 int GENERATED ALWAYS AS (f1 * 2) STORED,
+  f4 int GENERATED ALWAYS AS (f2 * 2) STORED
+);
+INSERT INTO gtestm VALUES (1, 5, 100);
+MERGE INTO gtestm t USING (VALUES (1, 10), (2, 20)) v(id, f1) ON t.id = v.id
+  WHEN MATCHED THEN UPDATE SET f1 = v.f1
+  WHEN NOT MATCHED THEN INSERT VALUES (v.id, v.f1, 200);
+SELECT * FROM gtestm ORDER BY id;
+DROP TABLE gtestm;
+
+-- views
+CREATE VIEW gtest1v AS SELECT * FROM gtest1;
+SELECT * FROM gtest1v;
+INSERT INTO gtest1v VALUES (4, 8);  -- error
+INSERT INTO gtest1v VALUES (5, DEFAULT);  -- ok
+INSERT INTO gtest1v VALUES (6, 66), (7, 77);  -- error
+INSERT INTO gtest1v VALUES (6, DEFAULT), (7, 77);  -- error
+INSERT INTO gtest1v VALUES (6, 66), (7, DEFAULT);  -- error
+INSERT INTO gtest1v VALUES (6, DEFAULT), (7, DEFAULT);  -- ok
+
+ALTER VIEW gtest1v ALTER COLUMN b SET DEFAULT 100;
+INSERT INTO gtest1v VALUES (8, DEFAULT);  -- error
+INSERT INTO gtest1v VALUES (8, DEFAULT), (9, DEFAULT);  -- error
+
+SELECT * FROM gtest1v;
+DELETE FROM gtest1v WHERE a >= 5;
+DROP VIEW gtest1v;
+
+-- CTEs
+WITH foo AS (SELECT * FROM gtest1) SELECT * FROM foo;
+
+-- inheritance
+CREATE TABLE gtest1_1 () INHERITS (gtest1);
+SELECT * FROM gtest1_1;
+\d gtest1_1
+INSERT INTO gtest1_1 VALUES (4);
+SELECT * FROM gtest1_1;
+SELECT * FROM gtest1;
+
+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);
+\d gtest_normal_child
+INSERT INTO gtest_normal (a) VALUES (1);
+INSERT INTO gtest_normal_child (a) VALUES (2);
+SELECT * FROM gtest_normal;
+
+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;
+
+-- test inheritance mismatches between parent and child
+CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS (a * 22) STORED) INHERITS (gtest1);  -- error
+CREATE TABLE gtestx (x int, b int DEFAULT 10) INHERITS (gtest1);  -- error
+CREATE TABLE gtestx (x int, b int GENERATED ALWAYS AS IDENTITY) INHERITS (gtest1);  -- error
+
+CREATE TABLE gtestxx_1 (a int NOT NULL, b int);
+ALTER TABLE gtestxx_1 INHERIT gtest1;  -- error
+CREATE TABLE gtestxx_2 (a int NOT NULL, b int GENERATED ALWAYS AS (a * 22) STORED);
+ALTER TABLE gtestxx_2 INHERIT gtest1;  -- error
+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
+DROP TABLE gtesty;
+
+CREATE TABLE gtesty (x int, b int GENERATED ALWAYS AS (x * 22) STORED);
+CREATE TABLE gtest1_2 () INHERITS (gtest1, gtesty);  -- error
+DROP TABLE gtesty;
+
+CREATE TABLE gtesty (x int, b int DEFAULT 55);
+CREATE TABLE gtest1_2 () INHERITS (gtest0, gtesty);  -- error
+DROP TABLE gtesty;
+
+-- test correct handling of GENERATED column that's only in child
+CREATE TABLE gtestp (f1 int);
+CREATE TABLE gtestc (f2 int GENERATED ALWAYS AS (f1+1) STORED) INHERITS(gtestp);
+INSERT INTO gtestc values(42);
+TABLE gtestc;
+UPDATE gtestp SET f1 = f1 * 10;
+TABLE gtestc;
+DROP TABLE gtestp CASCADE;
+
+-- 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;
+UPDATE gtest3 SET a = 22 WHERE a = 2;
+SELECT * FROM gtest3 ORDER BY a;
+
+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;
+UPDATE gtest3a SET a = 'bb' WHERE a = 'b';
+SELECT * FROM gtest3a ORDER BY a;
+
+-- COPY
+TRUNCATE gtest1;
+INSERT INTO gtest1 (a) VALUES (1), (2);
+
+COPY gtest1 TO stdout;
+
+COPY gtest1 (a, b) TO stdout;
+
+COPY gtest1 FROM stdin;
+3
+4
+\.
+
+COPY gtest1 (a, b) FROM stdin;
+
+SELECT * FROM gtest1 ORDER BY a;
+
+TRUNCATE gtest3;
+INSERT INTO gtest3 (a) VALUES (1), (2);
+
+COPY gtest3 TO stdout;
+
+COPY gtest3 (a, b) TO stdout;
+
+COPY gtest3 FROM stdin;
+3
+4
+\.
+
+COPY gtest3 (a, b) FROM stdin;
+
+SELECT * FROM gtest3 ORDER BY a;
+
+-- null values
+CREATE TABLE gtest2 (a int PRIMARY KEY, b int GENERATED ALWAYS AS (NULL) STORED);
+INSERT INTO gtest2 VALUES (1);
+SELECT * FROM gtest2;
+
+-- 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;
+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;
+
+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;
+
+-- 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;  -- fails
+ALTER TABLE gtest10 DROP COLUMN b CASCADE;  -- drops c too
+
+\d gtest10
+
+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
+SELECT a, c FROM gtest11s;  -- allowed
+SELECT gf1(10);  -- not allowed
+SELECT a, c FROM gtest12s;  -- allowed
+RESET ROLE;
+
+DROP FUNCTION gf1(int);  -- fail
+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
+
+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
+
+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
+
+-- 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
+
+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
+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);
+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);
+
+-- 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
+
+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;
+SELECT * FROM gtest22c WHERE b = 4;
+EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE b * 3 = 6;
+SELECT * FROM gtest22c WHERE b * 3 = 6;
+EXPLAIN (COSTS OFF) SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+SELECT * FROM gtest22c WHERE a = 1 AND b > 0;
+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
+CREATE TABLE gtest23x (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x) ON DELETE SET NULL);  -- error
+
+CREATE TABLE gtest23b (a int PRIMARY KEY, b int GENERATED ALWAYS AS (a * 2) STORED REFERENCES gtest23a (x));
+\d gtest23b
+
+INSERT INTO gtest23b VALUES (1);  -- ok
+INSERT INTO gtest23b VALUES (5);  -- error
+
+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
+
+-- 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
+
+-- 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);
+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
+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');
+CREATE TABLE gtest_child3 PARTITION OF gtest_parent FOR VALUES FROM ('2016-09-01') TO ('2016-10-01');
+INSERT INTO gtest_parent (f1, f2) VALUES ('2016-07-15', 1);
+SELECT * FROM gtest_parent;
+SELECT * FROM gtest_child;
+UPDATE gtest_parent SET f1 = f1 + 60, f2 = f2 + 1;
+SELECT * FROM gtest_parent;
+SELECT * FROM gtest_child3;
+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);
+CREATE TABLE gtest_parent (f1 date NOT NULL, f2 bigint, f3 bigint GENERATED ALWAYS AS (f2 * 2) STORED) PARTITION BY RANGE ((f3 * 3));
+
+-- 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;
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (b * 4) STORED;  -- error
+ALTER TABLE gtest25 ADD COLUMN x int GENERATED ALWAYS AS (z * 4) STORED;  -- error
+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;
+\d gtest25
+
+-- 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
+ALTER TABLE gtest27 ALTER COLUMN x TYPE numeric;
+\d gtest27
+SELECT * FROM gtest27;
+ALTER TABLE gtest27 ALTER COLUMN x TYPE boolean USING x <> 0;  -- error
+ALTER TABLE gtest27 ALTER COLUMN x DROP DEFAULT;  -- error
+-- 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
+-- 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
+\d gtest27
+SELECT * FROM gtest27;
+
+-- 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
+ALTER TABLE gtest29 ALTER COLUMN a DROP EXPRESSION IF EXISTS;  -- notice
+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;
+\d gtest29
+
+-- check that dependencies between columns have also been removed
+ALTER TABLE gtest29 DROP COLUMN a;  -- should not drop b
+\d gtest29
+
+-- 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
+\d gtest30_1
+DROP TABLE gtest30 CASCADE;
+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
+\d gtest30
+\d gtest30_1
+ALTER TABLE gtest30_1 ALTER COLUMN b DROP EXPRESSION;  -- error
+
+-- 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();
+
+CREATE TRIGGER gtest2b BEFORE INSERT OR UPDATE ON gtest26
+  FOR EACH ROW
+  WHEN (NEW.* IS NOT NULL)  -- error
+  EXECUTE PROCEDURE gtest_trigger_func();
+
+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);
+SELECT * FROM gtest26 ORDER BY a;
+UPDATE gtest26 SET a = a * -2;
+SELECT * FROM gtest26 ORDER BY a;
+DELETE FROM gtest26 WHERE a = -6;
+SELECT * FROM gtest26 ORDER BY a;
+
+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;
+
+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;
+SELECT * FROM gtest26 ORDER BY a;
+
+-- 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*