SET @old_instant=
(SELECT variable_value FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column');
CREATE TABLE t(a INT PRIMARY KEY, b INT, c INT, d INT, e INT)
ENGINE=InnoDB;
INSERT INTO t VALUES(1,2,3,4,5);
SET innodb_strict_mode = OFF;
SELECT * FROM t;
b	d	a	c	e
NULL	NULL	1	NULL	NULL
ALTER TABLE t DROP b, DROP c, DROP d, DROP e,
ADD COLUMN b INT, ALGORITHM=INSTANT;
ERROR 0A000: ALGORITHM=INSTANT is not supported for this operation. Try ALGORITHM=INPLACE
ALTER TABLE t CHANGE COLUMN b beta INT AFTER a, ALGORITHM=INSTANT;
ALTER TABLE t DROP e, DROP c, DROP d, ALGORITHM=INSTANT;
SELECT * FROM t;
a	beta
1	NULL
ALTER TABLE t DROP COLUMN beta, ALGORITHM=INSTANT;
ALTER TABLE t ADD COLUMN b INT NOT NULL, ALGORITHM=INSTANT;
ERROR 0A000: ALGORITHM=INSTANT is not supported for this operation. Try ALGORITHM=INPLACE
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
instants
256
ALTER TABLE t ADD COLUMN b INT NOT NULL;
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
instants
256
SELECT * FROM t;
a	b
1	0
ALTER TABLE t ADD COLUMN (c CHAR(255) NOT NULL, d BIGINT NOT NULL),
ALGORITHM=INSTANT;
UPDATE t SET b=b+1,d=d+1,c='foo';
SELECT * FROM t;
a	b	c	d
1	1	foo	1
SELECT variable_value-@old_instant instants
FROM information_schema.global_status
WHERE variable_name = 'innodb_instant_alter_column';
instants
502
DROP TABLE t;
