SET @old_concurrent_insert= @@global.concurrent_insert;
SET @@global.concurrent_insert= 0;
DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (kill_id INT);
INSERT INTO t1 VALUES(connection_id());
FLUSH TABLES WITH READ LOCK;
SELECT ((@id := kill_id) - kill_id) FROM t1;
((@id := kill_id) - kill_id)
0
KILL CONNECTION @id;
DROP TABLE t1;
SET @@global.concurrent_insert= @old_concurrent_insert;