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4e1e9ea6f3
From the very beginning, the default InnoDB transaction isolation level
REPEATABLE READ does not correspond to any well formed definition.
The main issue is the lack of write/write conflict detection.
To fix that and to make REPEATABLE READ correspond to Snapshot Isolation,
b8a6719889 introduced the Boolean
session variable innodb_snapshot_isolation. It was disabled by default
in order not to break any user applications.
In a new major version of MariaDB Server, we had better enable this
parameter by default.
70 lines
1.9 KiB
Text
70 lines
1.9 KiB
Text
-- source include/not_embedded.inc
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-- source include/have_innodb.inc
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--disable_warnings
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drop table if exists t1,t2;
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--enable_warnings
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# basic tests of semi-consistent reads
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connect (a,localhost,root,,);
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connect (b,localhost,root,,);
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connection a;
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set binlog_format=mixed;
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set session transaction isolation level repeatable read;
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create table t1(a int not null) engine=innodb DEFAULT CHARSET=latin1;
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insert into t1 values (1),(2),(3),(4),(5),(6),(7);
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set autocommit=0;
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# this should lock the entire table
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select * from t1 where a=3 lock in share mode;
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connection b;
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set binlog_format=mixed;
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set session transaction isolation level repeatable read;
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set autocommit=0;
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-- error ER_LOCK_WAIT_TIMEOUT
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update t1 set a=10 where a=5;
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commit;
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connection a;
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commit;
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connection b;
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# perform a semi-consisent read (and unlock non-matching rows)
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set innodb_snapshot_isolation=off;
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set session transaction isolation level read committed;
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update t1 set a=10 where a=5;
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connection a;
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-- error ER_LOCK_WAIT_TIMEOUT
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select * from t1 where a=2 for update;
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# this should lock the records (1),(2)
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select * from t1 where a=2 limit 1 for update;
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connection b;
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# semi-consistent read will skip non-matching locked rows a=1, a=2
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update t1 set a=11 where a=6;
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-- error ER_LOCK_WAIT_TIMEOUT
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update t1 set a=12 where a=2;
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-- error ER_LOCK_WAIT_TIMEOUT
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update t1 set a=13 where a=1;
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connection a;
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commit;
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connection b;
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update t1 set a=14 where a=1;
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commit;
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connection a;
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select * from t1;
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drop table t1;
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connection default;
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disconnect a;
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disconnect b;
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# Bug 39320
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create table t1 (a int, b int) engine=myisam;
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create table t2 (c int, d int, key (c)) engine=innodb;
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insert into t1 values (1,1);
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insert into t2 values (1,2);
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connect (a,localhost,root,,);
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connection a;
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set session transaction isolation level read committed;
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delete from t1 using t1 join t2 on t1.a = t2.c where t2.d in (1);
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connection default;
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disconnect a;
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drop table t1, t2;
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