SET @save_undo_logs = @@GLOBAL.innodb_undo_logs;
SET @save_frequency = @@GLOBAL.innodb_purge_rseg_truncate_frequency;
SET @save_truncate = @@GLOBAL.innodb_undo_log_truncate;
SET GLOBAL innodb_undo_log_truncate = 0;
SET GLOBAL innodb_undo_logs = 4;
SET GLOBAL innodb_purge_rseg_truncate_frequency = 1;
SET @trunc_start=
(SELECT variable_value FROM information_schema.global_status
WHERE variable_name = 'innodb_undo_truncations');
create table t1(keyc int primary key, c char(100)) engine = innodb;
create table t2(keyc int primary key, c char(100)) engine = innodb;
CREATE PROCEDURE populate_t1()
BEGIN
DECLARE i INT DEFAULT 1;
while (i <= 20000) DO
insert into t1 values (i, 'a');
SET i = i + 1;
END WHILE;
END |
CREATE PROCEDURE populate_t2()
BEGIN
DECLARE i INT DEFAULT 1;
while (i <= 20000) DO
insert into t2 values (i, 'a');
SET i = i + 1;
END WHILE;
END |
connect  con1,localhost,root,,;
begin;
call populate_t1();
connect  con2,localhost,root,,;
begin;
call populate_t2();
connection con1;
update t1 set c = 'mysql';
connection con2;
update t2 set c = 'mysql';
connection con1;
update t1 set c = 'oracle';
connection con2;
update t2 set c = 'oracle';
connection con1;
delete from t1;
connection con2;
delete from t2;
connection con1;
SET GLOBAL innodb_undo_log_truncate = 1;
commit;
disconnect con1;
connection con2;
commit;
disconnect con2;
connection default;
drop table t1, t2;
drop PROCEDURE populate_t1;
drop PROCEDURE populate_t2;
InnoDB		0 transactions not purged
SET GLOBAL innodb_undo_logs = @save_undo_logs;
SET GLOBAL innodb_purge_rseg_truncate_frequency = @save_frequency;
SET GLOBAL innodb_undo_log_truncate = @save_truncate;