This patch is the result of running
run-clang-tidy -fix -header-filter=.* -checks='-*,modernize-use-equals-default' .
Code style changes have been done on top. The result of this change
leads to the following improvements:
1. Binary size reduction.
* For a -DBUILD_CONFIG=mysql_release build, the binary size is reduced by
~400kb.
* A raw -DCMAKE_BUILD_TYPE=Release reduces the binary size by ~1.4kb.
2. Compiler can better understand the intent of the code, thus it leads
to more optimization possibilities. Additionally it enabled detecting
unused variables that had an empty default constructor but not marked
so explicitly.
Particular change required following this patch in sql/opt_range.cc
result_keys, an unused template class Bitmap now correctly issues
unused variable warnings.
Setting Bitmap template class constructor to default allows the compiler
to identify that there are no side-effects when instantiating the class.
Previously the compiler could not issue the warning as it assumed Bitmap
class (being a template) would not be performing a NO-OP for its default
constructor. This prevented the "unused variable warning".
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.
locks on the table
Fixing the partitioning specifics after TRUNCATE TABLE in
bug-42643 was fixed.
Reorganize of code to decrease the size of the giant switch
in mysql_execute_command, and to prepare for future parser
reengineering. Moved code into Sql_statement objects.
Updated patch according to davi's review comments.
libmysqld/CMakeLists.txt:
Added new files.
libmysqld/Makefile.am:
Added new files.
mysql-test/r/not_partition.result:
now returning error on partitioning commands
if partitioning is not enabled.
mysql-test/r/partition_disabled.result:
There is no partition handlerton, so it cannot
find the specified engine in the .frm file.
mysql-test/r/partition_truncate.result:
Updated test results.
mysql-test/suite/parts/inc/partition_mgm.inc:
Added check that TRUNCATE PARTITION does not delete on failure.
mysql-test/suite/parts/r/partition_debug_sync_innodb.result:
updated results.
mysql-test/suite/parts/r/partition_mgm_lc0_archive.result:
updated results.
mysql-test/suite/parts/r/partition_mgm_lc1_archive.result:
updated results.
mysql-test/suite/parts/r/partition_mgm_lc2_archive.result:
updated results.
mysql-test/suite/parts/t/partition_debug_sync_innodb.test:
Test case for this bug.
mysql-test/t/not_partition.test:
Added check for TRUNCATE PARTITION without partitioning.
mysql-test/t/partition_truncate.test:
Added test of TRUNCATE PARTITION on non partitioned table.
sql/CMakeLists.txt:
Added new files.
sql/Makefile.am:
Added new files.
sql/datadict.cc:
Moved out the storage engine check into an own
function, including assert for lock.
sql/datadict.h:
added dd_frm_storage_engine.
sql/sql_alter_table.cc:
moved the code for SQLCOM_ALTER_TABLE in mysql_execute_command
into its own file, and using the Sql_statement object to
prepare for future parser reengineering.
sql/sql_alter_table.h:
Created Sql_statement object for ALTER TABLE.
sql/sql_lex.cc:
resetting m_stmt.
sql/sql_lex.h:
Temporary hack for forward declaration of enum_alter_table_change_level.
sql/sql_parse.cc:
Moved out ALTER/ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE
from the giant switch into their own Sql_statement
objects.
sql/sql_parse.h:
Exporting check_merge_table_access.
sql/sql_partition_admin.cc:
created Sql_statement for
ALTER TABLE t ANALYZE/CHECK/OPTIMIZE/REPAIR/TRUNCATE
PARTITION. To be able to reuse the TABLE equivalents.
sql/sql_partition_admin.h:
Added Sql_statement of partition admin statements.
sql/sql_table.cc:
Moved table maintenance code into sql_table_maintenance.cc
sql/sql_table.h:
Moved table maintenance code into sql_table_maintenance.h
exporting functions used by sql_table_maintenance.
sql/sql_table_maintenance.cc:
Moved table maintenance code from sql_table.cc
sql/sql_table_maintenance.h:
Sql_statement objects for ANALYZE/CHECK/OPTIMIZE/REPAIR TABLE.
Also declaring the keycache functions.
sql/sql_truncate.cc:
Moved code from SQLCOM_TRUNCATE in mysql_execute_command into
Truncate_statement::execute.
Added check for partitioned table on TRUNCATE PARTITION.
Moved locking fix for partitioned table into
Alter_table_truncate_partition::execute.
sql/sql_truncate.h:
Truncate_statement declaration (sub class of Sql_statement).
sql/sql_yacc.yy:
Using the new Sql_statment objects.
