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Bug#11853126 RE-ENABLE CONCURRENT READS WHILE CREATING

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SECONDARY INDEX IN INNODB

The patches for Bug#11751388 and Bug#11784056 enabled concurrent
reads while creating secondary indexes in InnoDB. However, they
introduced a regression. This regression occured if ALTER TABLE
failed after the index had been added, for example during the
lock upgrade needed to update .FRM. If this happened, InnoDB
and the server got out of sync with regards to which indexes
actually existed. Therefore the patch for Bug#11815600 again
disabled concurrent reads.

This patch re-enables concurrent reads. The original regression
is fixed by splitting the ADD INDEX operation into two parts.
First the new index is created but not made active. This is
done while concurrent reads are allowed. The second part of
the operation makes the index active (or reverts the change).
This is done after lock upgrade, which prevents the original
regression.

In order to implement this change, the patch changes the storage
API for in-place index creation. handler::add_index() is split
into two functions, handler_add_index() and
handler::final_add_index(). The former for creating indexes without
making them visible and the latter for commiting (i.e. making
visible) new indexes or reverting the changes.

Large parts of this patch were written by Marko Mäkelä.

Test case added to innodb_mysql_lock.test.
This commit is contained in:
Jon Olav Hauglid
2011-06-01 10:06:55 +02:00
parent bd708b4240
commit f21fd6e40f
11 changed files with 578 additions and 235 deletions
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20
mysql-test/r/innodb_mysql_lock.result
View File

@ -153,6 +153,7 @@ DROP VIEW v1;
# KEY NO 0 FOR TABLE IN ERROR LOG
#
DROP TABLE IF EXISTS t1;
# Test 1: Secondary index
# Connection default
CREATE TABLE t1 (id INT PRIMARY KEY, value INT) ENGINE = InnoDB;
INSERT INTO t1 VALUES (1, 12345);
@ -164,9 +165,28 @@ id value
SET lock_wait_timeout=1;
ALTER TABLE t1 ADD INDEX idx(value);
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
ALTER TABLE t1 ADD INDEX idx(value);
ERROR HY000: Lock wait timeout exceeded; try restarting transaction
# Connection default
SELECT * FROM t1;
id value
1 12345
COMMIT;
DROP TABLE t1;
# Test 2: Primary index
CREATE TABLE t1(a INT NOT NULL, b INT NOT NULL) engine=innodb;
INSERT INTO t1 VALUES (1, 12345), (2, 23456);
# Connection con1
SET SESSION debug= "+d,alter_table_rollback_new_index";
ALTER TABLE t1 ADD PRIMARY KEY(a);
ERROR HY000: Unknown error
SELECT * FROM t1;
a b
1 12345
2 23456
# Connection default
SELECT * FROM t1;
a b
1 12345
2 23456
DROP TABLE t1;