# # Bug#18591145 - SOME MONOTONICALLY INCREASING STATUS VARIABLES DECREASES UNEXPECTEDLY # CREATE TABLE t1 (id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(64), val VARCHAR(1024)); # Insert 1 tuple to increment com_insert status. INSERT INTO t1(name, val) VALUES ('dummy', 0); connect con1, localhost, root,,; connection con1; SET DEBUG_SYNC='before_materialize_global_status_array SIGNAL change_user WAIT_FOR continue'; SET DEBUG_SYNC='after_materialize_global_status_array SIGNAL continue_change_user'; INSERT INTO t1(name, val) SELECT * FROM performance_schema.global_status WHERE variable_name='Handler_commit';; connection default; SET DEBUG_SYNC='now WAIT_FOR change_user'; SET DEBUG_SYNC='thd_cleanup_start SIGNAL continue WAIT_FOR continue_change_user'; connection con1; SET DEBUG_SYNC='RESET'; connection default; INSERT INTO t1(name, val) SELECT * FROM performance_schema.global_status WHERE variable_name='Handler_commit'; # With fix, Handler_commit status should be 2 (select insert during switch user + dictionary). # With binlog enabled, there is one more Handler_commit call. SET @binlog_handler_commit= IF(@@global.log_bin, 1, 0); SELECT (SELECT val FROM t1 WHERE id = 3) - (SELECT val FROM t1 WHERE id = 2) = 1 + @binlog_handler_commit; (SELECT val FROM t1 WHERE id = 3) - (SELECT val FROM t1 WHERE id = 2) = 1 + @binlog_handler_commit 1 disconnect con1; DROP TABLE t1;