DROP TABLE IF EXISTS t1;
CREATE TABLE t1 (a <INT_COLUMN>, b <CHAR_COLUMN>) ENGINE=<STORAGE_ENGINE> <CUSTOM_TABLE_OPTIONS>;
INSERT INTO t1 (a,b) VALUES (11,'foobar'),(12,'b');
SET LOW_PRIORITY_UPDATES = 0;
SET lock_wait_timeout = 4;
connect  con1,localhost,root,,;
SET lock_wait_timeout = 2;
SELECT a+SLEEP(1) FROM t1;
connection default;
UPDATE t1 SET a=a+10;
connect  con2,localhost,root,,;
SET lock_wait_timeout = 3;
SELECT a+SLEEP(1) FROM t1;
a+SLEEP(1)
21
22
connection con1;
a+SLEEP(1)
11
12
connection default;
SELECT a,b FROM t1;
a	b
21	foobar
22	b
connection con1;
SELECT a+SLEEP(1) FROM t1;
connection default;
UPDATE LOW_PRIORITY t1 SET a=a+20;
connection con2;
SELECT a+SLEEP(1) FROM t1;
a+SLEEP(1)
21
22
connection con1;
a+SLEEP(1)
21
22
connection default;
SELECT a,b FROM t1;
a	b
41	foobar
42	b
SET LOW_PRIORITY_UPDATES = 1;
connection con1;
SELECT a+SLEEP(1) FROM t1;
connection default;
UPDATE t1 SET a=a+30;
connection con2;
SELECT a+SLEEP(1) FROM t1;
a+SLEEP(1)
41
42
connection con1;
a+SLEEP(1)
41
42
connection default;
SELECT a,b FROM t1;
a	b
71	foobar
72	b
disconnect con1;
disconnect con2;
connection default;
DROP TABLE t1;