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mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00

Bug#49938: Failing assertion: inode or deadlock in fsp/fsp0fsp.c

Bug#54678: InnoDB, TRUNCATE, ALTER, I_S SELECT, crash or deadlock

- Incompatible change: truncate no longer resorts to a row by
row delete if the storage engine does not support the truncate
method. Consequently, the count of affected rows does not, in
any case, reflect the actual number of rows.

- Incompatible change: it is no longer possible to truncate a
table that participates as a parent in a foreign key constraint,
unless it is a self-referencing constraint (both parent and child
are in the same table). To work around this incompatible change
and still be able to truncate such tables, disable foreign checks
with SET foreign_key_checks=0 before truncate. Alternatively, if
foreign key checks are necessary, please use a DELETE statement
without a WHERE condition.

Problem description:

The problem was that for storage engines that do not support
truncate table via a external drop and recreate, such as InnoDB
which implements truncate via a internal drop and recreate, the
delete_all_rows method could be invoked with a shared metadata
lock, causing problems if the engine needed exclusive access
to some internal metadata. This problem originated with the
fact that there is no truncate specific handler method, which
ended up leading to a abuse of the delete_all_rows method that
is primarily used for delete operations without a condition.

Solution:

The solution is to introduce a truncate handler method that is
invoked when the engine does not support truncation via a table
drop and recreate. This method is invoked under a exclusive
metadata lock, so that there is only a single instance of the
table when the method is invoked.

Also, the method is not invoked and a error is thrown if
the table is a parent in a non-self-referencing foreign key
relationship. This was necessary to avoid inconsistency as
some integrity checks are bypassed. This is inline with the
fact that truncate is primarily a DDL operation that was
designed to quickly remove all data from a table.
This commit is contained in:
Davi Arnaut
2010-10-06 11:34:28 -03:00
parent 38194bf7a5
commit 5f911fa874
51 changed files with 1095 additions and 608 deletions

View File

@ -1941,7 +1941,7 @@ INSERT INTO t2 VALUES (3,2);
SET AUTOCOMMIT = 0;
START TRANSACTION;
TRUNCATE TABLE t1;
ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
ERROR 42000: Cannot truncate a table referenced in a foreign key constraint (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `test`.`t1` (`id`))
SELECT * FROM t1;
id
1
@ -1953,7 +1953,7 @@ id
2
START TRANSACTION;
TRUNCATE TABLE t1;
ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
ERROR 42000: Cannot truncate a table referenced in a foreign key constraint (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `test`.`t1` (`id`))
SELECT * FROM t1;
id
1
@ -1971,7 +1971,7 @@ id
2
COMMIT;
TRUNCATE TABLE t1;
ERROR 23000: Cannot delete or update a parent row: a foreign key constraint fails (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `t1` (`id`))
ERROR 42000: Cannot truncate a table referenced in a foreign key constraint (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `test`.`t1` (`id`))
SELECT * FROM t1;
id
1
@ -1983,9 +1983,12 @@ id
1
2
TRUNCATE TABLE t1;
ERROR 42000: Cannot truncate a table referenced in a foreign key constraint (`test`.`t2`, CONSTRAINT `t2_ibfk_1` FOREIGN KEY (`t1_id`) REFERENCES `test`.`t1` (`id`))
ROLLBACK;
SELECT * FROM t1;
id
1
2
TRUNCATE TABLE t2;
DROP TABLE t2;
DROP TABLE t1;
@ -2077,9 +2080,9 @@ i i
** error handling inside a row iteration.
**
DROP TRIGGER trg;
TRUNCATE TABLE t1;
TRUNCATE TABLE t2;
TRUNCATE TABLE t3;
DELETE FROM t1;
DELETE FROM t2;
DELETE FROM t3;
INSERT INTO t1 VALUES (1),(2),(3),(4);
INSERT INTO t3 VALUES (1),(2),(3),(4);
INSERT INTO t4 VALUES (3,3),(4,4);
@ -2105,9 +2108,9 @@ DROP TRIGGER trg;
**
** Induce an error midway through an AFTER-trigger
**
TRUNCATE TABLE t4;
TRUNCATE TABLE t1;
TRUNCATE TABLE t3;
DELETE FROM t4;
DELETE FROM t1;
DELETE FROM t3;
INSERT INTO t1 VALUES (1),(2),(3),(4);
INSERT INTO t3 VALUES (1),(2),(3),(4);
CREATE TRIGGER trg AFTER DELETE ON t1 FOR EACH ROW