create table t1(n int); insert into t1 values (1); lock tables t1 write; update low_priority t1 set n = 4; select n from t1; unlock tables; n 4 drop table t1; create table t1(n int); insert into t1 values (1); lock tables t1 read; update low_priority t1 set n = 4; select n from t1; unlock tables; n 1 drop table t1;