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92b2a911e5
In MDEV-515, we enabled an optimization where an insert into an
empty table will use table-level locking and undo logging.
This may break applications that expect row-level locking.
The SQL statements created by the mysqldump utility will include the
following:
SET unique_checks=0, foreign_key_checks=0;
We will use these flags to enable the table-level locked and logged
insert. Unless the parameters are set, INSERT will be executed in
the old way, with row-level undo logging and implicit record locks.
55 lines
1.1 KiB
SQL
55 lines
1.1 KiB
SQL
-- connect (con1,localhost,root,,)
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-- connect (con2,localhost,root,,)
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-- connection con1
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# Enable MDEV-515 table-level undo logging for insert into empty table
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SET foreign_key_checks=0, unique_checks=0;
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SET autocommit=0;
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SELECT * FROM t1 FOR UPDATE;
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-- if ($con1_extra_sql_present) {
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-- eval $con1_extra_sql
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-- }
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-- connection con2
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# Enable MDEV-515 table-level undo logging for insert into empty table
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SET foreign_key_checks=0, unique_checks=0;
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SET autocommit=0;
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SELECT * FROM t2 FOR UPDATE;
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-- if ($con2_extra_sql_present) {
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-- eval $con2_extra_sql
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-- }
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-- if ($con1_should_be_rolledback) {
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-- connection con1
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-- send
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INSERT INTO t2 VALUES (0);
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-- connection con2
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INSERT INTO t1 VALUES (0);
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ROLLBACK;
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-- connection con1
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-- error ER_LOCK_DEADLOCK
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-- reap
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-- }
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# else
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-- if (!$con1_should_be_rolledback) {
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-- connection con2
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-- send
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INSERT INTO t1 VALUES (0);
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-- connection con1
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INSERT INTO t2 VALUES (0);
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ROLLBACK;
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-- connection con2
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-- error ER_LOCK_DEADLOCK
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-- reap
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-- }
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-- connection default
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DELETE FROM t5_nontrans;
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-- disconnect con1
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-- disconnect con2
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