1. 29 Jun, 2011 1 commit
    • Marc Alff's avatar
      Bug#12565712 - 61205: "QUERIES PER SECOND AVG" VALUE IN STATUS OUTPUT IS INCORRECT · 6f1decbf
      Marc Alff authored
      Before this fix, a server executing 1009 queries in 1000 seconds would give a status of:
      Queries per second avg: 1.9
      The printf format used to print the decimal part, computed separately, is incorrect.
      
      With this fix, the correct result is printed:
      Queries per second avg: 1.009
      
      Tested manually, no test case provided.
      6f1decbf
  2. 28 Jun, 2011 3 commits
    • Marko Mäkelä's avatar
      Bug#12699505 Memory leak in row_create_index_for_mysql() · 8c988dc6
      Marko Mäkelä authored
      DB_COL_APPEARS_TWICE_IN_INDEX: Remove. This condition is already
      checked and reported by MySQL before passing the index definition to
      the storage engine.
      
      row_create_index_for_mysql(): Remove the redundant check for
      DB_COL_APPEARS_TWICE_IN_INDEX. When enforcing the column prefix index
      limit, invoke dict_mem_index_free(index) to plug the memory leak. In
      the loop, use index->n_def instead of dict_index_get_n_fields(index),
      because the latter would be 0 for indexes that have not been copied to
      the data dictionary cache.
      
      innodb-use-sys-malloc.test:
      
      Add test cases for attempting to trigger the error checks in
      row_create_index_for_mysql(). Before MySQL 5.5 and WL#5743, the leak
      is only reproducible if ha_innobase::max_supported_key_part_length()
      returned a higher limit than the one used in
      row_create_index_for_mysql().
      
      In MySQL 5.5 and later, the leak is reproducible with
      innodb_large_prefix=true.
      
      rb:688 approved by Jimmy Yang
      8c988dc6
    • Marko Mäkelä's avatar
      Merge mysql-5.1 to mysql-5.5. · cdecb914
      Marko Mäkelä authored
      cdecb914
    • Marko Mäkelä's avatar
      Bug#12595087 - 61191: Question about page_zip_available (clean up page0zip.c) · 0c54d44f
      Marko Mäkelä authored
      page_zip_dir_elems(): New function, refactored from page_zip_dir_size().
      
      page_zip_dir_size(): Use page_zip_dir_elems()
      
      page_zip_dir_start_offs(): New function: Gets an offset to the
      compressed page trailer (the dense page directory), including deleted
      records (the free list)
      
      page_zip_dir_start_low(page_zip, n_dense): Constness-preserving
      wrapper macro for page_zip_dir_start_offs().
      
      page_zip_dir_start(page_zip): Constness-preserving
      wrapper macro for page_zip_dir_start_offs().
      
      page_zip_decompress_node_ptrs(), page_zip_decompress_clust(): Replace
      a formula with a fully equivalent page_zip_dir_start_low() call.
      
      page_zip_write_rec(), page_zip_parse_write_node_ptr(),
      page_zip_write_node_ptr(), page_zip_write_trx_id_and_roll_ptr(),
      page_zip_clear_rec(): Replace a formula with an almost equivalent
      page_zip_dir_start() call.
      It is OK to replace page_dir_get_n_heap(page) with
      page_dir_get_n_heap(page_zip->data), because
      ut_ad(page_zip_header_cmp(page_zip, page)) or
      page_zip_validate(page_zip, page) asserts that the
      page headers are identical.
      
      rb:687 approved by Jimmy Yang
      0c54d44f
  3. 23 Jun, 2011 4 commits
    • Dmitry Shulga's avatar
    • Dmitry Shulga's avatar
      Fixed Bug#11756013 (formerly known as bug#47870): · bc7af175
      Dmitry Shulga authored
      BOGUS "THE TABLE MYSQL.PROC IS MISSING,..."
      
      There was a race condition between loading a stored routine
      (function/procedure/trigger) specified by fully qualified name
      SCHEMA_NAME.PROC_NAME and dropping the stored routine database.
      
      The problem was that there is a window for race condition when one server
      thread tries to load a stored routine being executed and the other thread
      tries to drop the stored routine schema.
      
      This condition race window exists in implementation of function
      mysql_change_db() called by db_load_routine() during loading of stored
      routine to cache. Function mysql_change_db() calls check_db_dir_existence()
      that might failed because specified database was dropped during concurrent
      execution of DROP SCHEMA statement. db_load_routine() calls mysql_change_db()
      with flag 'force_switch' set to 'true' value so when referenced db is not found
      then my_error() is not called and function mysql_change_db() returns ok.
      This shadows information about schema opening error in db_load_routine().
      Then db_load_routine() makes attempt to parse stored routine that is failed.
      This makes to return error to sp_cache_routines_and_add_tables_aux() but since
      during error generation a call to my_error wasn't made and hence
      THD::main_da wasn't set we set the generic "mysql.proc table corrupt" error
      when running sp_cache_routines_and_add_tables_aux().
      
      The fix is to install an error handler inside db_load_routine() for
      the mysql_op_change_db() call, and check later if the ER_BAD_DB_ERROR
      was caught.
      
      
      sql/sql_db.cc:
        Added synchronization point "before_db_dir_check" to emulate a race condition during
        processing of CALL/DROP SCHEMA.
      bc7af175
    • Marko Mäkelä's avatar
      Merge mysql-5.1 to mysql-5.5. · 7545f866
      Marko Mäkelä authored
      This patch was already pushed to mysql-5.5 by Inaam Rana.
      7545f866
    • Marko Mäkelä's avatar
      Bug#11753728 45225: Locking: hang if drop table with no timeout · d09b999f
      Marko Mäkelä authored
      Fix a failure of the re-enabled innodb-index.test in the embedded server.
      Apparently, the embedded server does not default to ENGINE=InnoDB when
      copying an InnoDB table by CREATE TABLE t2 SELECT * FROM t1;
      d09b999f
  4. 17 Jun, 2011 2 commits
    • Inaam Rana's avatar
      Bug 12635227 - 61188: DROP TABLE EXTREMELY SLOW · e60e6505
      Inaam Rana authored
      approved by: Marko
      rb://681
      
      Coalescing of free buf_page_t descriptors can prove to be one severe
      bottleneck in performance of compression. One such workload where it
      hurts badly is DROP TABLE. This patch removes buf_page_t allocations
      from buf_buddy and uses ut_malloc instead.
      In order to further reduce overhead of colaescing we no longer attempt
      to coalesce a block if the corresponding free_list is less than 16 in
      size.
      e60e6505
    • Jon Olav Hauglid's avatar
      Bug#12657095 YASSL ERROR MESSAGE CONTAINS TYPO · 7de029da
      Jon Olav Hauglid authored
      This patch fixes a typo in a YaSSL error message.
      7de029da
  5. 16 Jun, 2011 6 commits
    • Dmitry Lenev's avatar
      Fix for bug #12652385 - "61493: REORDERING COLUMNS · edfd31a0
      Dmitry Lenev authored
      TO POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED".
       
      ALTER TABLE MODIFY/CHANGE ... FIRST did nothing except renaming
      columns if new version of the table had exactly the same 
      structure as the old one (i.e. as result of such statement, names 
      of columns changed their order as specified but data in columns 
      didn't). The same thing happened for ALTER TABLE DROP COLUMN/ADD 
      COLUMN statements which were supposed to produce new version of
      table with exactly the same structure as the old version of table.
      I.e. in the latter case the result was the same as if old column 
      was renamed instead of being dropped and new column with default
      as value being created.
       
      Both these problems were caused by the fact that ALTER TABLE
      implementation incorrectly interpreted both these situations as 
      simple renaming of columns and assumed that in-place ALTER TABLE
      algorithm could have been used for them.
       
      This patch fixes this problem by ensuring that in cases when some
      column is moved to the first position or some column is dropped
      the default ALTER TABLE algorithm involving table copying is 
      always used. This is achieved by detecting such situations in
      mysql_prepare_alter_table() and setting Alter_info::change_level
      to ALTER_TABLE_DATA_CHANGED for them.
      
      mysql-test/r/alter_table.result:
        Added test for bug #12652385 - "61493: REORDERING COLUMNS TO
        POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED".
      mysql-test/t/alter_table.test:
        Added test for bug #12652385 - "61493: REORDERING COLUMNS TO
        POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED".
      sql/sql_table.cc:
        Changed mysql_prepare_alter_table() to detect situations in 
        which we some column moved to the first position or some column 
        is dropped and ensure that such ALTER TABLE statements won't
        be carried out using in-place algorithm. The latter could have 
        happened before this patch if new version of table had the same 
        structure as the old one (except the column names).
      edfd31a0
    • Vasil Dimov's avatar
      Silence bogus compiler warning introduced in · 0dfe86f5
      Vasil Dimov authored
      marko.makela@oracle.com-20110616072721-8bo92ctixq6eqavr
      0dfe86f5
    • Marko Mäkelä's avatar
      Bug #61341 buf_LRU_insert_zip_clean can be O(N) on LRU length · b0fc27dc
      Marko Mäkelä authored
      The buf_pool->zip_clean list is only needed for debugging, or for
      recomputing buf_pool->page_hash when resizing the buffer pool. Buffer
      pool resizing was never fully implemented. Remove the resizing code,
      and define buf_pool->zip_clean only in debug builds.
      
      buf_pool->zip_clean, buf_LRU_insert_zip_clean(): Enclose in
      #if defined UNIV_DEBUG || UNIV_BUF_DEBUG.
      
      buf_chunk_free(), buf_chunk_all_free(), buf_pool_shrink(),
      buf_pool_page_hash_rebuild(), buf_pool_resize(): Remove (unreachable code).
      
      rb:671 approved by Inaam Rana
      b0fc27dc
    • Marko Mäkelä's avatar
      Bug#12595087 - 61191: Question about page_zip_available · e4aa6667
      Marko Mäkelä authored
      There is an apparent problem with page_zip_clear_rec().
      In btr_cur_optimistic_update() we do this:
      
      	page_cur_delete_rec(page_cursor, index, offsets, mtr);
      ...
      	rec = btr_cur_insert_if_possible(cursor, new_entry, 0/*n_ext*/, mtr);
      	ut_a(rec); /* <- We calculated above the insert would fit */
      
      The problem is that page_cur_delete_rec() could fill the modification
      log while doing page_zip_clear_rec(), requiring recompression for the
      btr_cur_insert_if_possible(). In a pathological case, the data could
      fail to recompress.
      
      page_zip_clear_rec(): Leave the page modification log alone. Only
      clear the necessary fields.
      
      rb:673 approved by Jimmy Yang
      e4aa6667
    • Marko Mäkelä's avatar
      Re-enable the debug assertions for Bug#12650861. · 417a2679
      Marko Mäkelä authored
      Replace UNIV_BLOB_NULL_DEBUG with UNIV_DEBUG||UNIV_BLOB_LIGHT_DEBUG. 
      Fix known bogus failures.
      
      btr_cur_optimistic_update(): If rec_offs_any_null_extern(), assert that
      the current transaction is an incomplete transaction that is being
      rolled back in crash recovery.
      
      row_build(): If rec_offs_any_null_extern(), assert that the transaction
      that last updated the record was recovered during crash recovery
      (and will soon be rolled back).
      417a2679
    • Marko Mäkelä's avatar
      Bug#12612184 Race condition after btr_cur_pessimistic_update() · 5b4ceba5
      Marko Mäkelä authored
      btr_cur_compress_if_useful(), btr_compress(): Add the parameter ibool
      adjust. If adjust=TRUE, adjust the cursor position after compressing
      the page.
      
      btr_lift_page_up(): Return a pointer to the father page.
      
      BTR_KEEP_POS_FLAG: A new flag for btr_cur_pessimistic_update().
      
      btr_cur_pessimistic_update(): If *big_rec != NULL and flags &
      BTR_KEEP_POS_FLAG, keep the cursor positioned on the updated record.
      Also, do not release the index tree x-lock if *big_rec != NULL.
      
      btr_cur_mtr_commit_and_start(): Commits and restarts a
      mini-transaction so that it will retain an x-lock on index->lock and
      the page of the cursor. This is invoked when
      btr_cur_pessimistic_update() returns *big_rec != NULL.
      
      In all callers of btr_cur_pessimistic_update() that do not pass
      BTR_KEEP_POS_FLAG, assert that *big_rec == NULL.
      
      btr_cur_compress(): Unused function [in the built-in MySQL 5.1], remove.
      
      page_rec_get_nth(): Return the nth record on the page (an inverse
      function of page_rec_get_n_recs_before()). Refactored from
      page_get_middle_rec().
      
      page_get_middle_rec(): Invoke page_rec_get_nth().
      
      page_cur_insert_rec_zip_reorg(): Make use of the page directory
      shortcuts in page_rec_get_nth() instead of scanning the whole list of
      records.
      
      row_ins_clust_index_entry_by_modify(): Pass BTR_KEEP_POS_FLAG to
      btr_cur_pessimistic_update().
      
      row_ins_index_entry_low(): If row_ins_clust_index_entry_by_modify()
      returns a big_rec, invoke btr_cur_mtr_commit_and_start() in order to
      commit and start the mini-transaction without releasing the x-locks on
      index->lock and the cursor page, and write the big_rec. Releasing the
      page latch in mtr_commit() caused a race condition.
      
      row_upd_clust_rec(): Pass BTR_KEEP_POS_FLAG to
      btr_cur_pessimistic_update(). If it returns a big_rec, invoke
      btr_cur_mtr_commit_and_start() in order to commit and start the
      mini-transaction without releasing the x-locks on index->lock and the
      cursor page, and write the big_rec. Releasing the page latch in
      mtr_commit() caused a race condition.
      
      sync_thread_add_level(): Add the parameter ibool relock. When TRUE,
      bypass the latching order rules.
      
      rw_lock_add_debug_info(): For nested X-lock requests, pass relock=TRUE
      to sync_thread_add_level().
      
      rb:678 approved by Jimmy Yang
      5b4ceba5
  6. 15 Jun, 2011 1 commit
    • Marko Mäkelä's avatar
      Introduce UNIV_BLOB_NULL_DEBUG for temporarily hiding Bug#12650861. · a8629376
      Marko Mäkelä authored
      Some ut_a(!rec_offs_any_null_extern()) assertion failures are indicating
      genuine BLOB bugs, others are bogus failures when rolling back incomplete
      transactions at crash recovery. This needs more work, and until I get a
      chance to work on it, other testing must not be disrupted by this.
      a8629376
  7. 14 Jun, 2011 1 commit
    • Marko Mäkelä's avatar
      Merge a fix from mysql-5.5 to mysql-5.1: · 98d527d3
      Marko Mäkelä authored
      revno 2995.37.209
      revision id marko.makela@oracle.com-20110518120508-qhn7vz814vn77v5k
      parent marko.makela@oracle.com-20110517121555-lmple24qzxqkzep4
      timestamp: Wed 2011-05-18 15:05:08 +0300
      message:
        Fix a bogus UNIV_SYNC_DEBUG failure in the fix of Bug #59641
        or Oracle Bug #11766513.
      
        trx_undo_free_prepared(): Do not acquire or release trx->rseg->mutex.
        This code is invoked in the single-threaded part of shutdown, therefore
        a mutex is not needed.
      98d527d3
  8. 13 Jun, 2011 1 commit
  9. 10 Jun, 2011 4 commits
    • Karen Langford's avatar
      Merged from mysql-5.0 · e06e1767
      Karen Langford authored
      e06e1767
    • Karen Langford's avatar
      increase version number to 5.0.95 · 93823c52
      Karen Langford authored
      93823c52
    • Karen Langford's avatar
      Raise version number after cloning 5.1.58 · 9cfba6a7
      Karen Langford authored
      9cfba6a7
    • Dmitry Shulga's avatar
      Fixed bug#11753738 (formely known as bug#45235) - 5.1 DOES NOT SUPPORT 5.0-ONLY · 1fea8c1b
      Dmitry Shulga authored
      SYNTAX TRIGGERS IN ANY WAY
      
      Table with triggers which were using deprecated (5.0-only) syntax became
      unavailable for any DML and DDL after upgrade to 5.1 version of server.
      Attempt to execute any statement on such a table resulted in parsing
      error reported. Since this included DROP TRIGGER and DROP TABLE
      statements (actually, the latter was allowed but was not functioning
      properly for such tables) it was impossible to fix the problem without
      manual operations on .TRG and .TRN files in data directory.
      
      The problem was that failure to parse trigger body (due to 5.0-only
      syntax) when opening trigger file for a table prevented the table
      from being open. This made all operations on the table impossible
      (except DROP TABLE which due to peculiarity in its implementation
      dropped the table but left trigger files around).
      
      This patch solves this problem by silencing error which occurs when
      we parse trigger body during table open. Error message is preserved
      for the future use and table is marked as having a broken trigger.
      We also try to analyze parse tree to recover trigger name, which
      will be needed in order to drop the broken trigger. DML statements
      which invoke triggers on the table marked as having broken trigger
      are prohibited and emit saved error message. The same happens for
      DDL which change triggers except DROP TRIGGER and DROP TABLE which
      try their best to do what was requested. Table becomes no longer
      marked as having broken trigger when last such trigger is dropped.
      
      mysql-test/r/trigger-compat.result:
        Add results for test case for bug#45235
      mysql-test/t/trigger-compat.test:
        Add test case for bug#45235.
      sql/sp_head.cc:
        Added protection against MEM_ROOT double restoring to
        sp_head::restore_thd_mem_root() method. Since this
        method can be sometimes called twice during parsing
        of stored routine (the first time during normal flow
        of parsing, and the second time when a syntax error
        is detected) we need to shortcut execution of the
        method to avoid damaging MEM_ROOT by the second
        consecutive call to this method.
      sql/sql_trigger.cc:
        Added error handler Deprecated_trigger_syntax_handler to 
        catch non-OOM errors during parsing of trigger body.
        
        Added handling of parse errors into method 
        Table_triggers_list::check_n_load().
      sql/sql_trigger.h:
        Added new members to handle broken triggers and error messages.
      1fea8c1b
  10. 09 Jun, 2011 4 commits
    • Marko Mäkelä's avatar
      Disable a debug assertion that was added to track down Bug#12612184. · 4412b5da
      Marko Mäkelä authored
      row_build(): The record may contain null BLOB pointers when the server
      is rolling back an insert that was interrupted by a server crash.
      4412b5da
    • Dmitry Shulga's avatar
      Follow-up for patch of bug#11764334. · 53e4a852
      Dmitry Shulga authored
      53e4a852
    • Dmitry Shulga's avatar
      Fixed bug#11764334 (formerly bug#57156): ALTER EVENT CHANGES · fa913a0b
      Dmitry Shulga authored
      THE EVENT STATUS.
      
      Any ALTER EVENT statement on a disabled event enabled it back
      (unless this ALTER EVENT statement explicitly disabled the event).
      
      The problem was that during processing of an ALTER EVENT statement
      value of status field was overwritten unconditionally even if new
      value was not specified explicitly. As a consequence this field
      was set to default value for status which corresponds to ENABLE.
      
      The solution is to check if status field was explicitly specified in
      ALTER EVENT statement before assigning new value to status field.
      
      mysql-test/r/events_bugs.result:
        test's result for Bug#11764334 was added.
      mysql-test/t/events_bugs.test:
        new test for Bug#11764334 was added.
      sql/event_db_repository.cc:
        mysql_event_fill_row() was modified: set value for status field
        in events tables only in case if statement CREATE EVENT
        is being processed or if this value was set in ALTER EVENT
        statement.
        Event_db_repository::create_event was modified: removed redundant
        setting of status field after return from call to mysql_event_fill_row().
      sql/event_parse_data.h:
        Event_parse_data structure was modified: added flag
        status_changed that is set to true if status's value
        was changed in ALTER EVENT statement.
      sql/sql_yacc.yy:
        Set flag status_changed if status was set in ALTER EVENT
        statement.
      fa913a0b
    • Marko Mäkelä's avatar
      BLOB instrumentation for Bug#12612184 Race condition in row_upd_clust_rec() · 6348b737
      Marko Mäkelä authored
      If UNIV_DEBUG or UNIV_BLOB_LIGHT_DEBUG is enabled, add
      !rec_offs_any_null_extern() assertions, ensuring that records do not
      contain null pointers to externally stored columns in inappropriate
      places.
      
      btr_cur_optimistic_update(): Assert !rec_offs_any_null_extern().
      Incomplete records must never be updated or deleted. This assertion
      will cover also the pessimistic route.
      
      row_build(): Assert !rec_offs_any_null_extern(). Search tuples must
      never be built from incomplete index entries.
      
      row_rec_to_index_entry(): Assert !rec_offs_any_null_extern() unless
      ROW_COPY_DATA is requested. ROW_COPY_DATA is used for
      multi-versioning, and therefore it might be valid to copy the most
      recent (uncommitted) version while it contains a null pointer to
      off-page columns.
      
      row_vers_build_for_consistent_read(),
      row_vers_build_for_semi_consistent_read(): Assert !rec_offs_any_null_extern()
      on all versions except the most recent one.
      
      trx_undo_prev_version_build(): Assert !rec_offs_any_null_extern() on
      the previous version.
      
      rb:682 approved by Sunny Bains
      6348b737
  11. 07 Jun, 2011 2 commits
    • Ramil Kalimullin's avatar
      Bug#11764487: myisam corruption with insert ignore and invalid spatial data · 768b9a0e
      Ramil Kalimullin authored
      Problem: in case of wrong data insert into indexed GEOMETRY fields 
      (e.g. NULL value for a not NULL field) MyISAM reported 
      "ERROR 126 (HY000): Incorrect key file for table; try to repair it"
      due to misuse of the key deletion function.
      
      Fix: always use R-tree key functions for R-tree based indexes
      and B-tree key functions for B-tree based indexes.
      
      
      mysql-test/r/gis-rtree.result:
        Bug#11764487: myisam corruption with insert ignore and invalid spatial data
          - test result.
      mysql-test/t/gis-rtree.test:
        Bug#11764487: myisam corruption with insert ignore and invalid spatial data
          - test case.
      storage/myisam/mi_update.c:
        Bug#11764487: myisam corruption with insert ignore and invalid spatial data
          - handling update errors check for HA_ERR_NULL_IN_SPATIAL as well to be 
        consistent with mi_write();
          - always use keyinfo->ck_delete()/ck_insert() instead of _mi_ck_delete()/_mi_ck_write()
        to handle index properly, as it may be of B-tree or R-tree type.
      storage/myisam/mi_write.c:
        Bug#11764487: myisam corruption with insert ignore and invalid spatial data
          - always use keyinfo->ck_delete() instead of _mi_ck_delete() to handle
        index properly, as it may be of B-tree or R-tree type.
      768b9a0e
    • Guilhem Bichot's avatar
      This patch is for 5.5. · af5c95c2
      Guilhem Bichot authored
      WL#5914 remove option "--all" of the "perror" program.
      In 5.5 we just give a deprecation warning; in trunk we remove the option.
      af5c95c2
  12. 22 Jun, 2011 1 commit
    • Marko Mäkelä's avatar
      Bug#11753728 45225: Locking: hang if drop table with no timeout · e1aa1f87
      Marko Mäkelä authored
      Re-enable a test that was disabled as collateral damage.
      
      Starting with MySQL 5.5, queries will acquire and hold a shared meta-data lock
      (MDL) on tables they process, until the transaction is committed or
      rolled back. This will prevent DDL operations on the tables, such as creating
      an index.
      
      innodb-index.test: Use a second table for creating the index. The index will
      still be "too new" for the transaction that was started before the index
      creation was started.
      e1aa1f87
  13. 20 Jun, 2011 1 commit
  14. 17 Jun, 2011 2 commits
  15. 16 Jun, 2011 7 commits
    • Dmitry Lenev's avatar
      Merged fix for bug #12652385 - "61493: REORDERING COLUMNS · 2b992304
      Dmitry Lenev authored
      TO POSITION FIRST CAN CAUSE DATA TO BE CORRUPTED" into
      mysql-5.5 tree.
      2b992304
    • Matthias Leich's avatar
      Fix for · 699f0c06
      Matthias Leich authored
      Bug 12430414 - THE TEST PERFSCHEMA.SELECTS.TEST CAN AFFECT SUCCEEDING TESTS
      Bug 12430599 - THE TEST PERFSCHEMA.ONE_THREAD_PER_CON. CAN AFFECT SUCCEEDING TESTS
      Bug 12431153 - THE TEST PERFSCHEMA.PFS_UPGRADE CAN AFFECT SUCCEEDING TEST
      699f0c06
    • Dmitry Lenev's avatar
      Fix for bug #12641342 - "61401: UPDATE PERFORMANCE DEGRADES · 5b225518
      Dmitry Lenev authored
      GRADUALLY IF A TRIGGER EXISTS".
      
      This bug manifested itself in two ways:
      
      - Firstly execution of any data-changing statement which
        required prelocking (i.e. involved stored function or
        trigger) as part of transaction slowed down a bit all
        subsequent statements in this transaction. So performance
        in transaction which periodically involved such statements
        gradually degraded over time.
      - Secondly execution of any data-changing statement which
        required prelocking as part of transaction prevented
        concurrent FLUSH TABLES WITH READ LOCK from proceeding
        until the end of transaction instead of end of particular
        statement.
        
      The problem was caused by incorrect handling of metadata lock
      used in FTWRL implementation for statements requiring prelocked 
      mode. 
      Each statement which changes data acquires global IX lock
      with STATEMENT duration. This lock is supposed to block 
      concurrent FTWRL from proceeding until the statement ends.
      
      When entering prelocked mode, durations of all metadata locks
      acquired so far were changed to EXPLICIT, to prevent 
      substatements from releasing these locks. When prelocked mode
      was left, durations of metadata locks were changed to
      TRANSACTIONAL (with a few exceptions) so they can be properly
      released at the end of transaction. 
      Unfortunately, this meant that the global IX lock blocking
      FTWRL with STATEMENT duration was moved to TRANSACTIONAL
      duration after execution of statement requiring prelocking.
      
      Since each subsequent statement that required prelocking and
      tried to acquire global IX lock with STATEMENT duration got
      a new instance of MDL_ticket, which was later moved to
      TRANSACTIONAL duration, this led to unwarranted growth of
      number of tickets with TRANSACITONAL duration in this
      connection's MDL_context. As result searching for other
      tickets in it became slow and acquisition of other metadata
      locks by this transaction started to hog CPU.
      
      Moreover, this also meant that after execution of statement
      requiring prelocking concurrent FTWRL was blocked
      until the end of transaction instead of end of statement.
      
      This patch solves this problem by not moving locks to EXPLICIT
      duration when thread enters prelocked mode (unless it is a real 
      LOCK TABLES mode). This step turned out to be not really 
      necessary as substatements don't try to release metadata locks.
      Consequently, the global IX lock blocking FTWRL keeps its
      STATEMENT duration and is properly released at the end of
      statement and the above issue goes away.
      
      mysql-test/r/flush.result:
        Added test for bug #12641342 - "61401: UPDATE PERFORMANCE
        DEGRADES GRADUALLY IF A TRIGGER EXISTS".
      mysql-test/t/flush.test:
        Added test for bug #12641342 - "61401: UPDATE PERFORMANCE
        DEGRADES GRADUALLY IF A TRIGGER EXISTS".
      sql/mdl.h:
        Added comment describing various types of metadata lock
        duration.
      sql/sql_class.cc:
        Since we no longer change duration of metadata locks to EXPLICIT
        when entering prelocked mode (unless it is a real LOCK TABLES)
        there is no need to restore proper duration of the locks when
        leaving prelocked mode.
      sql/sql_class.h:
        Do not change duration of metadata locks to EXPLICIT when
        entering prelocking mode (unless it is a real LOCK TABLES).
        This allows to avoid problems with restoring correct duration
        when leaving this mode. It is possible to do this as
        substatements won't release metadata locks in any case.
      sql/sql_parse.cc:
        Added assert checking that we won't release metadata locks
        when in substatement.
      5b225518
    • Mayank Prasad's avatar
      BUG#12561297:LIBMYSQLD/EXAMPLE/MYSQL_EMBEDDED IS ABORTING. · 5adeda3a
      Mayank Prasad authored
      Issue:
      ------
      New test case mysql_embedded.test was failing on pb2.
      
      Description:
      ------------
      To run this test case executable libmysqld/examples/mysql_embedded is required.
      But as per /libmysqld/examples/cmake_install.cmake this executable doesn't get
      copied to <install_dir> when mysql is installed at <install_dir>.That is the
      reason it was passing in my local branch and failed on pb2 when pushed.
      
      Solution;
      ---------
      Added code in mysql-test-run.pl, which will try to see if this file exists.If
      It doesn't exist, test case will be skipped with a skip message. New code in
      mysql-test-run.pl looks only for directory libmysqld/examples/mysql_embedded
      because this is the only place where this file could/does exist.
      
      mysql-test/mysql-test-run.pl:
        Added new variable for mysql_embedded executable.
      mysql-test/t/disabled.def:
        enabled mysql_embedded.test which was disabled earlier.
      mysql-test/t/mysql_embedded.test:
        Modified test case to first verify if mysql_embedded executable exists. If
        it does not, skip the test.
      5adeda3a
    • Vasil Dimov's avatar
      Merge mysql-5.1 -> mysql-5.5 · 1ba283a9
      Vasil Dimov authored
      1ba283a9
    • Marko Mäkelä's avatar
      Merge mysql-5.1 to mysql-5.5. · f43adb80
      Marko Mäkelä authored
      f43adb80
    • Marko Mäkelä's avatar
      Merge mysql-5.1 to mysql-5.5. · 3400e0be
      Marko Mäkelä authored
      3400e0be