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create table t1 (
rowid int,
f1 int,
f2 int,
key i1 (f1, f2),
key i2 (f2)) engine=innodb;
show create table t1;
Table Create Table
t1 CREATE TABLE `t1` (
`rowid` int(11) DEFAULT NULL,
`f1` int(11) DEFAULT NULL,
`f2` int(11) DEFAULT NULL,
KEY `i1` (`f1`,`f2`),
KEY `i2` (`f2`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_uca1400_ai_ci
insert into `t1` (rowid, f1, f2) values (1, 1, 10), (2, 1, NULL);
connect a,localhost,root,,;
connect b,localhost,root,,;
connection a;
set innodb_snapshot_isolation=OFF;
start transaction with consistent snapshot;
connection b;
start transaction;
update t1 set f2 = 4 where f1 = 1 and f2 is null;
(b) Number of rows updated:
select row_count();
row_count()
1
insert into t1 values (3, 1, null);
(b) After update and insert query.
select rowid, f1, f2 from t1;
rowid f1 f2
1 1 10
2 1 4
3 1 NULL
commit;
connection a;
(a) Before the update statement is executed.
select rowid, f1, f2 from t1;
rowid f1 f2
1 1 10
2 1 NULL
SET SESSION debug_dbug="+d,bug14007649";
update t1 set f2 = 6 where f1 = 1 and f2 is null;
(a) Number of rows updated:
select row_count();
row_count()
1
(a) After the update statement is executed.
select rowid, f1, f2 from t1;
rowid f1 f2
1 1 10
2 1 NULL
3 1 6
commit;
"The trx with consistent snapshot ended."
select rowid, f1, f2 from t1;
rowid f1 f2
1 1 10
2 1 4
3 1 6
connection default;
disconnect a;
disconnect b;
drop table t1;
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