drop table if exists t1,t2;
connect a,localhost,root,,;
connect b,localhost,root,,;
connection a;
set binlog_format=mixed;
set session transaction isolation level repeatable read;
create table t1(a int not null) engine=innodb DEFAULT CHARSET=latin1;
insert into t1 values (1 ),(2 ),(3 ),(4 ),(5 ),(6 ),(7 );
set autocommit=0 ;
select * from t1 where a=3 lock in share mode;
a
3
connection b;
set binlog_format=mixed;
set session transaction isolation level repeatable read;
set autocommit=0 ;
update t1 set a=10 where a=5 ;
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
commit;
connection a;
commit;
connection b;
set innodb_snapshot_isolation=off;
set session transaction isolation level read committed;
update t1 set a=10 where a=5 ;
connection a;
select * from t1 where a=2 for update;
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
select * from t1 where a=2 limit 1 for update;
a
2
connection b;
update t1 set a=11 where a=6 ;
update t1 set a=12 where a=2 ;
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
update t1 set a=13 where a=1 ;
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
connection a;
commit;
connection b;
update t1 set a=14 where a=1 ;
commit;
connection a;
select * from t1;
a
14
2
3
4
10
11
7
drop table t1;
connection default;
disconnect a;
disconnect b;
create table t1 (a int, b int) engine=myisam;
create table t2 (c int, d int, key (c)) engine=innodb;
insert into t1 values (1 ,1 );
insert into t2 values (1 ,2 );
connect a,localhost,root,,;
connection a;
set session transaction isolation level read committed;
delete from t1 using t1 join t2 on t1.a = t2.c where t2.d in (1 );
connection default;
disconnect a;
drop table t1, t2;
Messung V0.5 in Prozent C=18 H=100 G=71
¤ Dauer der Verarbeitung: 0.9 Sekunden
(vorverarbeitet am 2026-10-08)
¤
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