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.
mysql-test/suite/innodb/t/innodb-truncate.test:
Add test cases for truncate and foreign key checks.
Also test that InnoDB resets auto-increment on truncate.
mysql-test/suite/innodb/t/innodb.test:
FK is not necessary, test is related to auto-increment.
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
mysql-test/suite/innodb/t/innodb_mysql.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
Use delete instead of truncate, test is used to check
the interaction of FKs, triggers and delete.
mysql-test/suite/parts/inc/partition_check.inc:
Fix typo.
mysql-test/suite/sys_vars/t/foreign_key_checks_func.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
mysql-test/t/mdl_sync.test:
Modify test case to reflect and ensure that truncate takes
a exclusive metadata lock.
mysql-test/t/trigger-trans.test:
Update error number, truncate is no longer invoked if
table is parent in a FK relationship.
sql/ha_partition.cc:
Reorganize the various truncate methods. delete_all_rows is now
passed directly to the underlying engines, so as truncate. The
code responsible for truncating individual partitions is moved
to ha_partition::truncate_partition, which is invoked when a
ALTER TABLE t1 TRUNCATE PARTITION p statement is executed.
Since the partition truncate no longer can be invoked via
delete, the bitmap operations are not necessary anymore. The
explicit reset of the auto-increment value is also removed
as the underlying engines are now responsible for reseting
the value.
sql/handler.cc:
Wire up the handler truncate method.
sql/handler.h:
Introduce and document the truncate handler method. It assumes
certain use cases of delete_all_rows.
Add method to retrieve the list of foreign keys referencing a
table. Method is used to avoid truncating tables that are
parent in a foreign key relationship.
sql/share/errmsg-utf8.txt:
Add error message for truncate and FK.
sql/sql_lex.h:
Introduce a flag so that the partition engine can detect when
a partition is being truncated. Used to give a special error.
sql/sql_parse.cc:
Function mysql_truncate_table no longer exists.
sql/sql_partition_admin.cc:
Implement the TRUNCATE PARTITION statement.
sql/sql_truncate.cc:
Change the truncate table implementation to use the new truncate
handler method and to not rely on row-by-row delete anymore.
The truncate handler method is always invoked with a exclusive
metadata lock. Also, it is no longer possible to truncate a
table that is parent in some non-self-referencing foreign key.
storage/archive/ha_archive.cc:
Rename method as the description indicates that in the future
this could be a truncate operation.
storage/blackhole/ha_blackhole.cc:
Implement truncate as no operation for the blackhole engine in
order to remain compatible with older releases.
storage/federated/ha_federated.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/heap/ha_heap.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/ibmdb2i/ha_ibmdb2i.cc:
Introduce truncate method that invokes delete_all_rows.
This is required to support partition truncate as this
form of truncate does not implement the drop and recreate
protocol.
storage/innobase/handler/ha_innodb.cc:
Rename delete_all_rows to truncate. InnoDB now does truncate
under a exclusive metadata lock.
Introduce and reorganize methods used to retrieve the list
of foreign keys referenced by a or referencing a table.
storage/myisammrg/ha_myisammrg.cc:
Introduce truncate method that invokes delete_all_rows.
This is required in order to remain compatible with earlier
releases where truncate would resort to a row-by-row delete.
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.
parameters don't match
Revert the changes of the default values of innodb_file_per_table
and innobase_file_format in 5.5, until WL#5135 is implemented.
parameters don't match
Revert the changes of the default values of innodb_file_per_table
and innobase_file_format in 5.5, until WL#5135 is implemented.
Fix compiler warning:
handler/ha_innodb.cc: In function 'bool innodb_show_status(handlerton*, THD*, bool (*)(THD*, const char*, uint, const char*, uint, const char*, uint))':
handler/ha_innodb.cc:7539:7: error: variable 'result' set but not used [-Werror=unused-but-set-variable]
Fix compiler warning:
handler/ha_innodb.cc: In function 'bool innodb_show_status(handlerton*, THD*, bool (*)(THD*, const char*, uint, const char*, uint, const char*, uint))':
handler/ha_innodb.cc:7539:7: error: variable 'result' set but not used [-Werror=unused-but-set-variable]
Fix compiler warning:
handler/ha_innodb.cc: In function 'void innobase_drop_database(handlerton*, char*)':
handler/ha_innodb.cc:5969:6: error: variable 'error' set but not used [-Werror=unused-but-set-variable]
Fix compiler warning:
handler/ha_innodb.cc: In function 'void innobase_drop_database(handlerton*, char*)':
handler/ha_innodb.cc:5969:6: error: variable 'error' set but not used [-Werror=unused-but-set-variable]
------------------------------------------------------------
revno: 3550
revision-id: marko.makela@oracle.com-20100824081003-v4ecy0tga99cpxw2
parent: marko.makela@oracle.com-20100823102854-t1clrojqis2ley36
committer: Marko Mäkelä <marko.makela@oracle.com>
branch nick: 5.1-innodb
timestamp: Tue 2010-08-24 11:10:03 +0300
message:
Bug#55832: selects crash too easily when innodb_force_recovery>3
dict_update_statistics_low(): Create bogus statistics for those
indexes that cannot be accessed because of the innodb_force_recovery
setting.
ha_innobase::info(): Calculate statistics for each index, even if
innodb_force_recovery is set. Fill in bogus data for those indexes
that are not accessed because of the innodb_force_recovery setting.
------------------------------------------------------------
revno: 3550
revision-id: marko.makela@oracle.com-20100824081003-v4ecy0tga99cpxw2
parent: marko.makela@oracle.com-20100823102854-t1clrojqis2ley36
committer: Marko Mäkelä <marko.makela@oracle.com>
branch nick: 5.1-innodb
timestamp: Tue 2010-08-24 11:10:03 +0300
message:
Bug#55832: selects crash too easily when innodb_force_recovery>3
dict_update_statistics_low(): Create bogus statistics for those
indexes that cannot be accessed because of the innodb_force_recovery
setting.
ha_innobase::info(): Calculate statistics for each index, even if
innodb_force_recovery is set. Fill in bogus data for those indexes
that are not accessed because of the innodb_force_recovery setting.
dict_update_statistics_low(): Create bogus statistics for those
indexes that cannot be accessed because of the innodb_force_recovery
setting.
ha_innobase::info(): Calculate statistics for each index, even if
innodb_force_recovery is set. Fill in bogus data for those indexes
that are not accessed because of the innodb_force_recovery setting.
dict_update_statistics_low(): Create bogus statistics for those
indexes that cannot be accessed because of the innodb_force_recovery
setting.
ha_innobase::info(): Calculate statistics for each index, even if
innodb_force_recovery is set. Fill in bogus data for those indexes
that are not accessed because of the innodb_force_recovery setting.
This patch doesn't get rid of the need to acquire the dict_sys->mutex but
reduces the need to keep the mutex locked for the duration of the query
to fsp_get_available_space_in_free_extents() from ha_innobase::info().
rb://390.
