set default_storage_engine=innodb; set @old_dbug=@@global.debug_dbug; SET @saved_frequency = @@GLOBAL.innodb_purge_rseg_truncate_frequency; SET GLOBAL innodb_purge_rseg_truncate_frequency = 1; CREATE TABLE `t` ( `a` BLOB, `b` BLOB, `c` BLOB GENERATED ALWAYS AS (CONCAT(a,b)) VIRTUAL, `h` VARCHAR(10) DEFAULT NULL, `i` int ) ENGINE=InnoDB; INSERT INTO t VALUES (REPEAT('g', 16000), REPEAT('x', 16000), DEFAULT, "kk", 1); INSERT INTO t VALUES (REPEAT('a', 16000), REPEAT('b', 16000), DEFAULT, "mm", 2); CREATE INDEX idx ON t(c(100)); SET global debug_dbug="+d,ib_purge_virtual_index_callback"; UPDATE t SET a = REPEAT('m', 16000) WHERE a like "aaa%"; InnoDB 0 transactions not purged SET global debug_dbug=@old_dbug; DROP TABLE t; CREATE TABLE t ( a TINYBLOB, b TINYBLOB, c TINYBLOB GENERATED ALWAYS AS (CONCAT(a,b)) VIRTUAL, h VARCHAR(10) DEFAULT NULL, i INT ) ROW_FORMAT=COMPACT ENGINE=InnoDB; INSERT INTO t VALUES (REPEAT('g', 100), REPEAT('x', 100), DEFAULT, "kk", 1); INSERT INTO t VALUES (REPEAT('a', 100), REPEAT('b', 100), DEFAULT, "mm", 2); CREATE INDEX idx ON t(c(100)); SET global debug_dbug="+d,ib_purge_virtual_index_callback"; UPDATE t SET a = REPEAT('m', 100) WHERE a like "aaa%"; InnoDB 0 transactions not purged SET global debug_dbug=@old_dbug; DROP TABLE t; CREATE TABLE t1 ( id INT NOT NULL, store_id INT NOT NULL, x INT GENERATED ALWAYS AS (id + store_id) ) PARTITION BY RANGE (store_id) ( PARTITION p0 VALUES LESS THAN (6), PARTITION p1 VALUES LESS THAN (11), PARTITION p2 VALUES LESS THAN (16), PARTITION p3 VALUES LESS THAN (21) ); insert into t1 values(1, 2, default); insert into t1 values(3, 4, default); insert into t1 values(3, 12, default); insert into t1 values(4, 18, default); CREATE INDEX idx ON t1(x); SET global debug_dbug="+d,ib_purge_virtual_index_callback"; UPDATE t1 SET id = 10 WHERE id = 1; InnoDB 0 transactions not purged SET global debug_dbug=@old_dbug; DROP TABLE t1; connect con1,localhost,root,,; connection default; CREATE TABLE t1 (a INT, b INT); INSERT INTO t1(a, b) VALUES (1, 1), (2, 2), (3, 3); connection con1; # disable purge CREATE TABLE t0 (a INT) ENGINE=InnoDB; BEGIN; SELECT * FROM t0; a connection default; DELETE FROM t1 WHERE a = 1; UPDATE t1 SET a = 4, b = 4 WHERE a = 3; INSERT INTO t1(a, b) VALUES (5, 5); SET DEBUG_SYNC= 'inplace_after_index_build SIGNAL uncommitted WAIT_FOR purged'; ALTER TABLE t1 ADD COLUMN c INT GENERATED ALWAYS AS(a+b), ADD INDEX idx (c), ALGORITHM=INPLACE, LOCK=NONE; ERROR 0A000: LOCK=NONE is not supported. Reason: INPLACE ADD or DROP of virtual columns cannot be combined with other ALTER TABLE actions. Try LOCK=SHARED ALTER TABLE t1 ADD COLUMN c INT GENERATED ALWAYS AS(a+b), ADD INDEX idx (c), ALGORITHM=INPLACE, LOCK=SHARED; connection con1; SET DEBUG_SYNC= 'now WAIT_FOR uncommitted'; # enable purge COMMIT; # wait for purge to process the deleted records. InnoDB 0 transactions not purged SET DEBUG_SYNC= 'now SIGNAL purged'; connection default; /* connection default */ ALTER TABLE t1 ADD COLUMN c INT GENERATED ALWAYS AS(a+b), ADD INDEX idx (c), ALGORITHM=INPLACE, LOCK=SHARED; SHOW CREATE TABLE t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) DEFAULT NULL, `b` int(11) DEFAULT NULL, `c` int(11) GENERATED ALWAYS AS (`a` + `b`) VIRTUAL, KEY `idx` (`c`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 SELECT * FROM t1; a b c 2 2 4 4 4 8 5 5 10 DROP TABLE t1; CREATE TABLE t1 (a INT, b INT, c INT GENERATED ALWAYS AS(a+b)); INSERT INTO t1(a, b) VALUES (1, 1), (2, 2), (3, 3), (4, 4); connection con1; # disable purge BEGIN; SELECT * FROM t0; a connection default; DELETE FROM t1 WHERE a = 1; UPDATE t1 SET a = 2, b = 2 WHERE a = 5; INSERT INTO t1(a, b) VALUES (6, 6); SET DEBUG_SYNC= 'inplace_after_index_build SIGNAL uncommitted WAIT_FOR purged'; ALTER TABLE t1 ADD INDEX idx (c), ALGORITHM=INPLACE, LOCK=NONE; connection con1; SET DEBUG_SYNC= 'now WAIT_FOR uncommitted'; DELETE FROM t1 WHERE a = 3; UPDATE t1 SET a = 7, b = 7 WHERE a = 4; INSERT INTO t1(a, b) VALUES (8, 8); # enable purge COMMIT; # wait for purge to process the deleted/updated records. InnoDB 2 transactions not purged SET DEBUG_SYNC= 'now SIGNAL purged'; disconnect con1; connection default; /* connection default */ ALTER TABLE t1 ADD INDEX idx (c), ALGORITHM=INPLACE, LOCK=NONE; SHOW CREATE TABLE t1; Table Create Table t1 CREATE TABLE `t1` ( `a` int(11) DEFAULT NULL, `b` int(11) DEFAULT NULL, `c` int(11) GENERATED ALWAYS AS (`a` + `b`) VIRTUAL, KEY `idx` (`c`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 SELECT * FROM t1; a b c 2 2 4 7 7 14 6 6 12 8 8 16 DROP TABLE t0, t1; create table t (a blob, b blob, c blob as (concat(a,b)), h varchar(10), index (c(100))); insert t(a,b,h) values (repeat('g', 16000), repeat('x', 16000), "kk"); insert t(a,b,h) values (repeat('a', 16000), repeat('b', 16000), "mm"); set global debug_dbug="+d,ib_purge_virtual_index_callback"; connect prevent_purge, localhost, root; start transaction with consistent snapshot; connection default; update t set a = repeat('m', 16000) where a like "aaa%"; connect con1, localhost, root; lock table t write; disconnect prevent_purge; connection default; select variable_value>1 from information_schema.global_status where variable_name='innodb_purge_trx_id_age'; variable_value>1 0 disconnect con1; start transaction with consistent snapshot; commit; InnoDB 0 transactions not purged select variable_value>1 from information_schema.global_status where variable_name='innodb_purge_trx_id_age'; variable_value>1 0 set global debug_dbug=@old_dbug; drop table t; set debug_sync=reset; SET GLOBAL innodb_purge_rseg_truncate_frequency = @saved_frequency;