#
# Bug#18591145 - SOME MONOTONICALLY INCREASING STATUS VARIABLES DECREASES UNEXPECTEDLY
#
show variables like "show_COMPATIBILITY_56";
Variable_name	Value
show_compatibility_56	ON
set global SHOW_COMPATIBILITY_56 = 1;
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,,;
SET DEBUG_SYNC='before_preparing_global_status_array SIGNAL change_user WAIT_FOR continue';
SET DEBUG_SYNC='after_preparing_global_status_array SIGNAL continue_change_user';
INSERT INTO t1(name, val) SELECT * FROM INFORMATION_SCHEMA.global_status WHERE variable_name='com_insert';;
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;
Warnings:
Warning	1287	'INFORMATION_SCHEMA.GLOBAL_STATUS' is deprecated and will be removed in a future release. Please use performance_schema.global_status instead
SET DEBUG_SYNC='RESET';
connection default;
INSERT INTO t1(name, val)
SELECT * FROM INFORMATION_SCHEMA.global_status WHERE variable_name='com_insert';
Warnings:
Warning	1287	'INFORMATION_SCHEMA.GLOBAL_STATUS' is deprecated and will be removed in a future release. Please use performance_schema.global_status instead
# With fix, difference of com_insert status should be "0" here.
SELECT (SELECT val FROM t1 WHERE id = 2) - (SELECT val FROM t1 WHERE id = 3);
(SELECT val FROM t1 WHERE id = 2) - (SELECT val FROM t1 WHERE id = 3)
0
# Testing the same scenario with performance_schema.
set global SHOW_COMPATIBILITY_56 = 0;
truncate t1;
# Insert 1 tuple to increment com_insert status.
INSERT INTO t1(name, val) VALUES ('dummy', 0);
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 1 (select insert during switch user).
SELECT (SELECT val FROM t1 WHERE id = 3) - (SELECT val FROM t1 WHERE id = 2);
(SELECT val FROM t1 WHERE id = 3) - (SELECT val FROM t1 WHERE id = 2)
1
set global SHOW_COMPATIBILITY_56=1;
disconnect con1;
DROP TABLE t1;