CAN LEAD TO MISSING TABLES
Overview
--------
If the FOREIGN_KEY_CHECKS system variable is set to 0, it is
possible to break a foreign key constraint by changing the type
or character set of the foreign key column, or by dropping the
foreign key index (without carrying out corresponding changes on
another table in the relationship).
If we subsequently set FOREIGN_KEY_CHECKS to 1 and execute ALTER
TABLE involving the COPY algorithm on such a table, the following
happens:
1) If ALTER TABLE does not contain a RENAME clause, the attempt
to install the new version of the table instead of the old one
will fail due to the fact that the inconsistency will be
detected. An attempt to revert the partially executed alter
table operation by restoring the old table definition will
fail as well due to FOREIGN_KEY_CHECKS == 1. As a result, the
table being altered will be lost.
2) If ALTER TABLE contains the RENAME clause, the inconsistency
will not be detected (most probably due to other bugs). But if
an attempt to install the new version of the table fails (for
example, due to a failure when updating triggers associated
with the table), reverting the partially executed alter table
by restoring the old table definition will fail too. So the
table being altered might be lost as well.
Suggested fix
-------------
The suggested fix is to temporarily unset the option bit
representing FOREIGN_KEY_CHECKS when the old table definition is
restored while reverting the partially executed operation.
"
revision-id: sanja@askmonty.org-20110511110948-4kdevwzomvk56y1w
committer: sanja@askmonty.org
branch nick: work-maria-5.1-CREATE-merge
timestamp: Wed 2011-05-11 14:09:48 +0300
Bugfix: New table creation/renaming block added if old encoded table present
"
the old behavior was less inconsistent than the new one.
In the new one the error message was sometimes different (under LOCK TABLES e.g.),
and there were race conditions (if this CREATE happened when a concurrent ALTER
has renamed the old table away but haven't put the new table in place)
The old one was like "(when using old table names) for DML #mysql50# prefix
is optional, for DDL it's required".
Generalized support for auto-updated and/or auto-initialized timestamp
and datetime columns. This patch is a reimplementation of MySQL's
"WL#5874: CURRENT_TIMESTAMP as DEFAULT for DATETIME columns". In order to
ease future merges, this implementation reused few function and variable
names from MySQL's patch, however the implementation is quite different.
TODO:
The only unresolved problem in this patch is the semantics of LOAD DATA for
TIMESTAMP and DATETIME columns in the cases when there are missing or NULL
columns. I couldn't fully comprehend the logic behind MySQL's behavior and
its relationship with their own documentation, so I left the results to be
more consistent with all other LOAD cases.
The problematic test cases can be seen by running the test file function_defaults,
and observing the test case differences. Those were left on purpose for discussion.
sql/sql_insert.cc:
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
******
CREATE ... IF NOT EXISTS may do nothing, but
it is still not a failure. don't forget to my_ok it.
sql/sql_table.cc:
small cleanup
******
small cleanup
Silence a warning about old table name when InnoDB tests whether the
format has changed using a nonexistent table name.
Reviewed by: bar@mysql.com, marko.makela@oracle.com
breaks SBR
This pre-requisite patch refactors the code for dropping tables, used
by DROP TABLE and DROP DATABASE. The patch moves the code for acquiring
metadata locks out of mysql_rm_table_part2() and makes it the
responsibility of the caller. This in preparation of changing the
DROP DATABASE implementation to acquire all metadata locks before any
changes are made. mysql_rm_table_part2() is renamed
mysql_rm_table_no_locks() to reflect the change.
The ALTER PARTITION and SELECT seemed to be deadlocked
when having innodb_thread_concurrency = 1.
Problem was that there was unreleased latches
in the ALTER PARTITION thread which was needed
by the SELECT thread to be able to continue.
Solution was to release the latches by commit
before requesting upgrade to exclusive MDL lock.
Updated according to reviewers comments (3).
mysql-test/r/partition_innodb.result:
updated test result
mysql-test/t/partition_innodb.test:
added test
sql/sql_partition.cc:
Moved implicit commit into mysql_change_partition
so that if latches are taken, they are always released
before waiting on exclusive lock.
sql/sql_table.cc:
refactored the code to prepare and commit
around copy_data_between_tables, to be able
to reuse it in mysql_change_partitions
sql/sql_table.h:
exporting mysql_trans_prepare/commit_alter_copy_data
temp table
This patch introduces two key changes in the replication's behavior.
Firstly, it reverts part of BUG#51894 which puts any update to temporary tables
into the trx-cache. Now, updates to temporary tables are handled according to
the type of their engines as a regular table.
Secondly, an unsafe mixed statement, (i.e. a statement that access transactional
table as well non-transactional or temporary table, and writes to any of them),
are written into the trx-cache in order to minimize errors in the execution when
the statement logging format is in use.
Such changes has a direct impact on which statements are classified as unsafe
statements and thus part of BUG#53259 is reverted.
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.
DATABASE with open HANDLER"
Remove LOCK_create_db, database name locks, and use metadata locks instead.
This exposes CREATE/DROP/ALTER DATABASE statements to the graph-based
deadlock detector in MDL, and paves the way for a safe, deadlock-free
implementation of RENAME DATABASE.
Database DDL statements will now take exclusive metadata locks on
the database name, while table/view/routine DDL statements take
intention exclusive locks on the database name. This prevents race
conditions between database DDL and table/view/routine DDL.
(e.g. DROP DATABASE with concurrent CREATE/ALTER/DROP TABLE)
By adding database name locks, this patch implements
WL#4450 "DDL locking: CREATE/DROP DATABASE must use database locks" and
WL#4985 "DDL locking: namespace/hierarchical locks".
The patch also changes code to use init_one_table() where appropriate.
The new lock_table_names() function requires TABLE_LIST::db_length to
be set correctly, and this is taken care of by init_one_table().
This patch also adds a simple template to help work with
the mysys HASH data structure.
Most of the patch was written by Konstantin Osipov.
This patch:
- Moves all definitions from the mysql_priv.h file into
header files for the component where the variable is
defined
- Creates header files if the component lacks one
- Eliminates all include directives from mysql_priv.h
- Eliminates all circular include cycles
- Rename time.cc to sql_time.cc
- Rename mysql_priv.h to sql_priv.h
