mariadb

Tree: 237dfb742f

Author	SHA1	Message	Date
Davi Arnaut	5f911fa874	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.	15 years ago
Alexander Nozdrin	d2159e37f2	Bug#27480 (Extend CREATE TEMPORARY TABLES privilege to allow temp table operations) -- prerequisite patch #3. Rename open_temporary_table() to open_table_uncached(). open_temporary_table() will be introduced in following patches to open temporary tables for a statement.	16 years ago
Mattias Jonsson	25ae81f133	Bug#49907: ALTER TABLE ... TRUNCATE PARTITION does not wait for 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.	16 years ago
Konstantin Osipov	f8bfa3287d	A fix for Bug#41158 "DROP TABLE holds LOCK_open during unlink()". Remove acquisition of LOCK_open around file system operations, since such operations are now protected by metadata locks. Rework table discovery algorithm to not require LOCK_open. No new tests added since all MDL locking operations are covered in lock.test and mdl_sync.test, and as long as these tests pass despite the increased concurrency, consistency must be unaffected.	16 years ago
Davi Arnaut	a10ae35328	Bug#34043: Server loops excessively in _checkchunk() when safemalloc is enabled Essentially, the problem is that safemalloc is excruciatingly slow as it checks all allocated blocks for overrun at each memory management primitive, yielding a almost exponential slowdown for the memory management functions (malloc, realloc, free). The overrun check basically consists of verifying some bytes of a block for certain magic keys, which catches some simple forms of overrun. Another minor problem is violation of aliasing rules and that its own internal list of blocks is prone to corruption. Another issue with safemalloc is rather the maintenance cost as the tool has a significant impact on the server code. Given the magnitude of memory debuggers available nowadays, especially those that are provided with the platform malloc implementation, maintenance of a in-house and largely obsolete memory debugger becomes a burden that is not worth the effort due to its slowness and lack of support for detecting more common forms of heap corruption. Since there are third-party tools that can provide the same functionality at a lower or comparable performance cost, the solution is to simply remove safemalloc. Third-party tools can provide the same functionality at a lower or comparable performance cost. The removal of safemalloc also allows a simplification of the malloc wrappers, removing quite a bit of kludge: redefinition of my_malloc, my_free and the removal of the unused second argument of my_free. Since free() always check whether the supplied pointer is null, redudant checks are also removed. Also, this patch adds unit testing for my_malloc and moves my_realloc implementation into the same file as the other memory allocation primitives.	16 years ago
Jon Olav Hauglid	41a3dfe490	A 5.5 version of the fix for Bug #54360 "Deadlock DROP/ALTER/CREATE 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.	16 years ago
Davi Arnaut	3cc56cb5ad	Bug#42643: InnoDB does not support replication of TRUNCATE TABLE Post-merge fix: Pass the right parameter type to open_and_lock_tables. Passing FALSE ensures that derived table handling is disabled, truncate only operates on base tables.	16 years ago
Davi Arnaut	2d3e5019d4	Bug#42643: InnoDB does not support replication of TRUNCATE TABLE Post-merge fix: Retrieve handler statistics to workaround quirks of the archive storage engine.	16 years ago
Davi Arnaut	3c279d9a5a	Bug#42643: InnoDB does not support replication of TRUNCATE TABLE The problem was that TRUNCATE TABLE didn't take a exclusive lock on a table if it resorted to truncating via delete of all rows in the table. Specifically for InnoDB tables, this could break proper isolation as InnoDB ends up aborting some granted locks when truncating a table. The solution is to take a exclusive metadata lock before TRUNCATE TABLE can proceed. This guarantees that no other transaction is using the table. Incompatible change: Truncate via delete no longer fails if sql_safe_updates is activated (this was a undocumented side effect).	16 years ago

11 Commits (237dfb742f016801356693f1c29fceb34cbcd42f)