An error occurred fetching the project authors.
- 20 Apr, 2011 1 commit
-
-
unknown authored
Analysis: The wrong result is a consquence of sorting the subquery result and then selecting only the first row due to the artificial LIMIT 1 introduced by the fix_fields phase. Normally, if there is an ORDER BY in a subquery, the ORDER is removed (Item_in_subselect::select_in_like_transformer), however if a GROUP BY is transformed into ORDER, this happens later, after the removal of the ORDER clause of subqueries, so we end up with a subquery with an ORDER clause, and an artificially added LIMIT 1. The reason why the same works in the main 5.3 without MWL#89, is that the 5.3 performs all subquery transformations, including IN->EXISTS before JOIN::optimize(). The beginning of JOIN::optimize does: if (having || (select_options & OPTION_FOUND_ROWS)) select_limit= HA_POS_ERROR; which sets the limit back to infinity, thus 5.3 sorts the whole subquery result, and IN performs the lookup into all subquery result rows. Solution: Sorting of subqueries without LIMIT is meaningless. Since LIMIT in subqueries is not supported, the patch removes sorting by setting join->skip_sort_order= true for each subquery JOIN object. This improves a number of execution plans to not perform unnecessary sorting at all.
-
- 08 Mar, 2011 1 commit
-
-
unknown authored
Analysis: The assert failed because the execution code for partial matching is designed with the assumption that NULLs on the left side are detected as early as possible, and a NULL result is returned before any lookups are performed at all. However, in the case of an Item_cache object on the left side, null was not detected properly, because detection was done via Item::is_null(), which is not implemented at all for Item_cache, and resolved to the default Item::is_null() which always returns FALSE. Solution: Use the property Item::null_value instead of is_null(), which is properly updated for Item_cache objects as well.
-
- 03 Mar, 2011 1 commit
-
-
unknown authored
Analysis: The reason for the crash was that the inner subquery was executed via a scan on a final temporary table applied after all other operations. This final operation is implemented by changing the contents of the JOIN object of the subquery to represent a table scan over the temp table. At the same time query optimization of the outer subquery required evaluation of the inner subquery, which happened before the actual EXPLAIN. The evaluation left the JOIN object of the inner subquery in the changed state, where it represented a table scan over a temp table, and EXPLAIN crashed because the temp table is not associated with any table reference (TABLE_LIST object). The reason the JOIN was not restored was because its saving/restoration was controlled by the join->select_lex->uncacheable flag, which was not set in the case of materialization. Solution: In the methods Item_in_subselect::[single | row]_value_transformer() set: select_lex->uncacheable|= UNCACHEABLE_EXPLAIN; In addition, for symmetry, change: master_unit->uncacheable|= UNCACHEABLE_EXPLAIN; instead of UNCACHEABLE_DEPENDENT because if a subquery was not dependent initially, the changed methods do not change this fact. The subquery may later become correlated if it is transformed to an EXISTS query, but it may stay uncorrelated if executed via materialization.
-
- 18 Feb, 2011 1 commit
-
-
Vladislav Vaintroub authored
-
- 10 Feb, 2011 1 commit
-
-
unknown authored
Fixed a memory leak found by valgrind. The memory leak was a result of JOINs corresponding to subselects in a global ORDER BY of a UNION not being cleaned up because the fake_select of the UNION didn't point down to the subquery select.
-
- 18 Jan, 2011 1 commit
-
-
unknown authored
Analysis: The cause for the failing assert was that between preparation and execution of a DELETE prepared statement, the server reverted back all changes of the item tree. Since the substitution of Item_in_subselect by an Item_in_optimizer was recorded via change_item_tree, thus the rollback of the item tree affected the substitution as well. As a result the execution of the PS called Item_in_subselect::val_int(), which was never supposed to be called. Solution: Replace change_item_tree with assignment. This is OK because the Item objects used for substitution are created in PS memory.
-
- 28 Dec, 2010 1 commit
-
-
Kent Boortz authored
- Removed files specific to compiling on OS/2 - Removed files specific to SCO Unix packaging - Removed "libmysqld/copyright", text is included in documentation - Removed LaTeX headers for NDB Doxygen documentation - Removed obsolete NDB files - Removed "mkisofs" binaries - Removed the "cvs2cl.pl" script - Changed a few GPL texts to use "program" instead of "library"
-
- 15 Dec, 2010 1 commit
-
-
unknown authored
Post-review fixes. Intermediate commit to address review points 1.1, 1.2, 1.3, 1.4, 1.5, and 3.1, 3.2, 3.3.
-
- 14 Dec, 2010 2 commits
-
-
unknown authored
Analysis: The assert failed because st_select_lex::print() was called for subqueries as follows: Item_subselect::print() -> subselect_single_select_engine::print() -> st_select_lex::print() It was Item_subselect::fix_fields() that set the thd by calling set_thd(), so when this print() was called before fix_fields(), subselect_engine::thd was NULL. Solution: The patch makes all constructors of all subselect_engine classes to take a THD parameter. The default subselect_single_select_engine engine is created early during parse time, in the Item_subselect::init call, so we pass the correct THD object already at this point.
-
Sergey Glukhov authored
--Bug#52157 various crashes and assertions with multi-table update, stored function --Bug#54475 improper error handling causes cascading crashing failures in innodb/ndb --Bug#57703 create view cause Assertion failed: 0, file .\item_subselect.cc, line 846 --Bug#57352 valgrind warnings when creating view --Recently discovered problem when a nested materialized derived table is used before being populated and it leads to incorrect result We have several modes when we should disable subquery evaluation. The reasons for disabling are different. It could be uselessness of the evaluation as in case of 'CREATE VIEW' or 'PREPARE stmt', or we should disable subquery evaluation if tables are not locked yet as it happens in bug#54475, or too early evaluation of subqueries can lead to wrong result as it happened in Bug#19077. Main problem is that if subquery items are treated as const they are evaluated in ::fix_fields(), ::fix_length_and_dec() of the parental items as a lot of these methods have Item::val_...() calls inside. We have to make subqueries non-const to prevent unnecessary subquery evaluation. At the moment we have different methods for this. Here is a list of these modes: 1. PREPARE stmt; We use UNCACHEABLE_PREPARE flag. It is set during parsing in sql_parse.cc, mysql_new_select() for each SELECT_LEX object and cleared at the end of PREPARE in sql_prepare.cc, init_stmt_after_parse(). If this flag is set subquery becomes non-const and evaluation does not happen. 2. CREATE|ALTER VIEW, SHOW CREATE VIEW, I_S tables which process FRM files We use LEX::view_prepare_mode field. We set it before view preparation and check this flag in ::fix_fields(), ::fix_length_and_dec(). Some bugs are fixed using this approach, some are not(Bug#57352, Bug#57703). The problem here is that we have a lot of ::fix_fields(), ::fix_length_and_dec() where we use Item::val_...() calls for const items. 3. Derived tables with subquery = wrong result(Bug19077) The reason of this bug is too early subquery evaluation. It was fixed by adding Item::with_subselect field The check of this field in appropriate places prevents const item evaluation if the item have subquery. The fix for Bug19077 fixes only the problem with convert_constant_item() function and does not cover other places(::fix_fields(), ::fix_length_and_dec() again) where subqueries could be evaluated. Example: CREATE TABLE t1 (i INT, j BIGINT); INSERT INTO t1 VALUES (1, 2), (2, 2), (3, 2); SELECT * FROM (SELECT MIN(i) FROM t1 WHERE j = SUBSTRING('12', (SELECT * FROM (SELECT MIN(j) FROM t1) t2))) t3; DROP TABLE t1; 4. Derived tables with subquery where subquery is evaluated before table locking(Bug#54475, Bug#52157) Suggested solution is following: -Introduce new field LEX::context_analysis_only with the following possible flags: #define CONTEXT_ANALYSIS_ONLY_PREPARE 1 #define CONTEXT_ANALYSIS_ONLY_VIEW 2 #define CONTEXT_ANALYSIS_ONLY_DERIVED 4 -Set/clean these flags when we perform context analysis operation -Item_subselect::const_item() returns result depending on LEX::context_analysis_only. If context_analysis_only is set then we return FALSE that means that subquery is non-const. As all subquery types are wrapped by Item_subselect it allow as to make subquery non-const when it's necessary. mysql-test/r/derived.result: test case mysql-test/r/multi_update.result: test case mysql-test/r/view.result: test case mysql-test/suite/innodb/r/innodb_multi_update.result: test case mysql-test/suite/innodb/t/innodb_multi_update.test: test case mysql-test/suite/innodb_plugin/r/innodb_multi_update.result: test case mysql-test/suite/innodb_plugin/t/innodb_multi_update.test: test case mysql-test/t/derived.test: test case mysql-test/t/multi_update.test: test case mysql-test/t/view.test: test case sql/item.cc: --removed unnecessary code sql/item_cmpfunc.cc: --removed unnecessary checks --THD::is_context_analysis_only() is replaced with LEX::is_ps_or_view_context_analysis() sql/item_func.cc: --refactored context analysis checks sql/item_row.cc: --removed unnecessary checks sql/item_subselect.cc: --removed unnecessary code --added DBUG_ASSERT into Item_subselect::exec() which asserts that subquery execution can not happen if LEX::context_analysis_only is set, i.e. at context analysis stage. --Item_subselect::const_item() Return FALSE if LEX::context_analysis_only is set. It prevents subquery evaluation in ::fix_fields & ::fix_length_and_dec at context analysis stage. sql/item_subselect.h: --removed unnecessary code sql/mysql_priv.h: --Added new set of flags. sql/sql_class.h: --removed unnecessary code sql/sql_derived.cc: --added LEX::context_analysis_only analysis intialization/cleanup sql/sql_lex.cc: --init LEX::context_analysis_only field sql/sql_lex.h: --New LEX::context_analysis_only field sql/sql_parse.cc: --removed unnecessary code sql/sql_prepare.cc: --removed unnecessary code --added LEX::context_analysis_only analysis intialization/cleanup sql/sql_select.cc: --refactored context analysis checks sql/sql_show.cc: --added LEX::context_analysis_only analysis intialization/cleanup sql/sql_view.cc: --added LEX::context_analysis_only analysis intialization/cleanup
-
- 29 Nov, 2010 1 commit
-
-
Michael Widenius authored
Changed rows_read and rows_sent status variables to be longlong (to avoid compiler warnings) sql/item_func.cc: Fixed wrong usage of alias sql/item_subselect.cc: Changed buffer size to ulonglong to be able detect buffers bigger than size_t sql/item_subselect.h: Changed buffer size to ulonglong to be able detect buffers bigger than size_t sql/multi_range_read.cc: Fixed compiler warning by using correct type for function argument sql/mysqld.cc: Changed rows_read and rows_sent status variables to be longlong sql/opt_subselect.h: Fixed compiler warning by using correct type for function argument sql/sql_class.cc: Changed rows_read and rows_sent status variables to be longlong sql/sql_class.h: Changed rows_read and rows_sent status variables to be longlong Changed max_nulls_in_row to uint as this is number of columns in row. This fixed some compiler warnings. sql/sql_select.cc: Added casts to avoid compiler warnings storage/heap/ha_heap.cc: Initilize different types separate storage/oqgraph/ha_oqgraph.cc: Fixed argument to store(longlong) to avoid compiler warnings
-
- 22 Nov, 2010 1 commit
-
-
unknown authored
Analysis: Single-row subqueries are not considered expensive and are evaluated both during EXPLAIN in to detect errors like "Subquery returns more than 1 row", and during optimization to perform constant optimization. The cause for the failed ASSERT is in JOIN::join_free, where we set bool full= (!select_lex->uncacheable && !thd->lex->describe); Thus for EXPLAIN statements full == FALSE, and as a result the call to JOIN::cleanup doesn't call JOIN_TAB::cleanup which should have called table->disable_keyread(). Solution: Consider all kinds of subquery predicates as expensive.
-
- 02 Nov, 2010 1 commit
-
-
Michael Widenius authored
Fixed compiler warnings. include/queues.h: Added prototype for queue_replace() mysys/queues.c: Fixed wrong queue_replace() mysys/thr_alarm.c: Added DBUG_PRINT sql/item_subselect.cc: Check return value of ha_rnd_init(). (Fixes compiler warnings) sql/sql_class.cc: Fixed wrong test sql/sql_show.cc: Removed not used variable.
-
- 27 Oct, 2010 1 commit
-
-
unknown authored
The set of Ordered keys of a rowid merge engine is dense. Thus when we decide not to create a key for a column that has only NULLs, this column shouldn't be counted. Notice that the caller has already precomputed the correct total number of keys that should be created.
-
- 26 Oct, 2010 1 commit
-
-
unknown authored
The cause for this bug is that MariaDB 5.3 still processes derived tables (subqueries in the FROM clause) by fully executing them during the parse phase. This will be remedied by MWL#106 once merged into the main 5.3. The assert statement is triggered when MATERIALIZATION is ON for EXPLAIN EXTENDED for derived tables with an IN subquery as follows: - mysql_parse calls JOIN::exec for the derived table as if it is regular execution (not explain). - When materialization is ON, this call goes all the way to subselect_hash_sj_engine::exec, which creates a partial match engine because of NULL presence. - In order to proceed with normal execution, the hash_sj engine substitutes itself with the created partial match engine. - After the parse phase it turns out that this execution was part of EXPLAIN EXTENDED, which in turn calls Item_cond::print -> ... -> Item_subselect::print, which calls engine->print(). Since subselect_hash_sj_engine::exec substituted the current Item_subselect engine with a partial match engine, eventually we call its ::print() method. However the partial match engines are designed only for execution, hence there is no implementation of this print() method. The fix temporarily removes the assert, until this code is merged with MWL#106.
-
- 23 Oct, 2010 1 commit
-
-
unknown authored
Added missing logic to handle the case when subquery tables are optimized away early during optimization.
-
- 18 Oct, 2010 1 commit
-
-
Sergey Glukhov authored
create_sort_index() function overwrites original JOIN_TAB::type field. At re-execution of subquery overwritten JOIN_TAB::type(JT_ALL) is used instead of JT_FT. It misleads test_if_skip_sort_order() and the function tries to find suitable key for the order that should not be allowed for FULLTEXT(JT_FT) table. The fix is to restore JOIN_TAB strucures for subselect on re-execution for EXPLAIN. Additional fix: Update TABLE::maybe_null field which affects list_contains_unique_index() behaviour as it could have the value(maybe_null==TRUE) based on the assumption that this join is outer (see setup_table_map() func). mysql-test/r/explain.result: test case mysql-test/t/explain.test: test case sql/item_subselect.cc: Make subquery uncacheable in case of EXPLAIN. It allows to keep original JOIN_TAB::type(see JOIN::save_join_tab) and restore it on re-execution. sql/sql_select.cc: -restore JOIN_TAB strucures for subselect on re-execution for EXPLAIN -Update TABLE::maybe_null field as it could have the value(maybe_null==TRUE) based on the assumption that this join is outer(see setup_table_map() func). This change is not related to the crash problem but affects EXPLAIN results in the test case.
-
- 05 Oct, 2010 1 commit
-
-
unknown authored
Added/corrected/improved comments.
-
- 01 Oct, 2010 1 commit
-
-
Sergey Glukhov authored
The crash happens because original join table is replaced with temporary table at execution stage and later we attempt to use this temporary table in select_describe. It might happen that Item_subselect::update_used_tables() method which sets const_item flag is not called by some reasons (no where/having conditon in subquery for example). It prevents JOIN::join_tmp creation and breaks original join. The fix is to call ::update_used_tables() before ::const_item() check. mysql-test/r/ps.result: test case mysql-test/t/ps.test: test case sql/item_subselect.cc: call ::update_used_tables() before ::const_item() check.
-
- 30 Sep, 2010 1 commit
-
-
unknown authored
Phase 3: Implementation of re-optimization of subqueries with injected predicates and cost comparison between Materialization and IN->EXISTS strategies. The commit contains the following known problems: - The implementation of EXPLAIN has not been re-engineered to reflect the changes in subquery optimization. EXPLAIN for subqueries is called during the execute phase, which results in different code paths during JOIN::optimize and thus in differing EXPLAIN messages for constant/system tables. - There are some valgrind warnings that need investigation - Several EXPLAINs with minor differences need to be reconsidered after fixing the EXPLAIN problem above. This patch also adds one extra optimizer_switch: 'in_to_exists' for complete manual control of the subquery execution strategies.
-
- 16 Sep, 2010 1 commit
-
-
unknown authored
Reset correctly the LIMIT and the uncacheable flag of a subquery when executing it via materialization.
-
- 09 Sep, 2010 1 commit
-
-
Alexey Kopytov authored
result Row subqueries producing no rows were not handled as UNKNOWN values in row comparison expressions. That was a result of the following two problems: 1. Item_singlerow_subselect did not mark the resulting row value as NULL/UNKNOWN when no rows were produced. 2. Arg_comparator::compare_row() did not take into account that a whole argument may be NULL rather than just individual scalar values. Before bug#34384 was fixed, the above problems were hidden because an uninitialized (i.e. without any stored value) cached object would appear as NULL for scalar values in a row subquery returning an empty result. After the fix Arg_comparator::compare_row() would try to evaluate uninitialized cached objects. Fixed by removing the aforementioned problems. mysql-test/r/row.result: Added a test case for bug #54190. mysql-test/r/subselect.result: Updated the result for a test relying on wrong behavior. mysql-test/t/row.test: Added a test case for bug #54190. sql/item_cmpfunc.cc: If either of the argument rows is NULL, return NULL as the result of comparison. sql/item_subselect.cc: Adjust null_value for Item_singlerow_subselect depending on whether a row has been produced by the row subquery.
-
- 07 Sep, 2010 1 commit
-
-
Martin Hansson authored
The EXISTS transformation has additional switches to catch the known corner cases that appear when transforming an IN predicate into EXISTS. Guarded conditions are used which are deactivated when a NULL value is seen in the outer expression's row. When the inner query block supplies NULL values, however, they are filtered out because no distinction is made between the guarded conditions; guarded NOT x IS NULL conditions in the HAVING clause that filter out NULL values cannot be de-activated in isolation from those that match values or from the outer expression or NULL's. The above problem is handled by making the guarded conditions remember whether they have rejected a NULL value or not, and index access methods are taking this into account as well. The bug consisted of 1) Not resetting the property for every nested loop iteration on the inner query's result. 2) Not propagating the NULL result properly from inner query to IN optimizer. 3) A hack that may or may not have been needed at some point. According to a comment it was aimed to fix #2 by returning NULL when FALSE was actually the result. This caused failures when #2 was properly fixed. The hack is now removed. The fix resolves all three points.
-
- 06 Sep, 2010 2 commits
-
-
unknown authored
Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/compare.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/group_by.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect3.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect3_jcl6.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect4.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect_cache.result: Added test suite for LP BUG#615760 mysql-test/r/subselect_mat.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect_no_mat.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect_no_opts.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect_no_semijoin.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect_sj.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/r/subselect_sj_jcl6.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/suite/pbxt/r/subselect.result: Cache parameters print added in EXPLAIN EXTENDED output. mysql-test/t/subselect_cache.test: Cache parameters print added in EXPLAIN EXTENDED output. sql/item.cc: Item::set_expr_cache result fixed according to its description. Cache parameters print added in EXPLAIN EXTENDED output. sql/item.h: Cache parameters print added in EXPLAIN EXTENDED output. sql/item_cmpfunc.cc: Check on double cache assignment added into the transformation methods. sql/item_cmpfunc.h: Check on double cache assignment added into the transformation methods. sql/item_subselect.cc: Check on double cache assignment added into the transformation methods. sql/item_subselect.h: Check on double cache assignment added into the transformation methods. sql/sql_expression_cache.cc: Cache parameters print added. sql/sql_expression_cache.h: Cache parameters print added. sql/sql_select.cc: Removed unused method (now it is impossible to make double transformation with the cache). sql/sql_select.h: Removed unused method.
-
unknown authored
-
- 05 Sep, 2010 1 commit
-
-
unknown authored
Fixes for multiple problems/bugs/test failures that resulted from moving subquery optimization from the execution phase to the optimization phase.
-
- 30 Aug, 2010 1 commit
-
-
unknown authored
The bug is a result of the following change by Monty: Revision Id: monty@askmonty.org-20100716073301-gstby2062nqd42qv Timestamp: Fri 2010-07-16 10:33:01 +0300 Where Monty changed the queues interface and implementation. The fix adjusts the queue_remove call to the new interface. mysql-test/r/subselect_partial_match.result: Added new file for tests related to MWL#89. mysql-test/t/subselect_partial_match.test: Added new file for tests related to MWL#89.
-
- 18 Jul, 2010 2 commits
-
-
unknown authored
Step2 in the separation of the creation of IN->EXISTS equi-join conditions from their injection. The goal of this separation is to make it possible that the IN->EXISTS conditions can be used for cost estimation without actually modifying the subquery. This patch separates row_value_in_to_exists_transformer() into two methods: - create_row_value_in_to_exists_cond(), and - inject_row_value_in_to_exists_cond() The patch performs minimal refactoring of the code so that it is easier to solve problems resulting from the separation. There is a lot to be simplified in this code, but this will be done separately.
-
unknown authored
Step1 in the separation of the creation of IN->EXISTS equi-join conditions from their injection. The goal of this separation is to make it possible that the IN->EXISTS conditions can be used for cost estimation without actually modifying the subquery. This patch separates single_value_in_to_exists_transformer() into two methods: - create_single_value_in_to_exists_cond(), and - inject_single_value_in_to_exists_cond() The patch performs minimal refactoring of the code so that it is easier to solve problems resulting from the separation. There is a lot to be simplified in this code, but this will be done separately.
-
- 16 Jul, 2010 3 commits
-
-
Michael Widenius authored
The issue was that we didn't always check result of ha_rnd_init() which caused a problem for handlers that returned an error in this code. - Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked. - Added ha_rnd_init_with_error() that prints error on failure. - Checked all usage of ha_rnd_init() and ensure we generate an error message on failures. - Changed init_read_record() to return 1 on failure. sql/create_options.cc: Fixed wrong printf sql/event_db_repository.cc: Check result from init_read_record() sql/events.cc: Check result from init_read_record() sql/filesort.cc: Check result from ha_rnd_init() sql/ha_partition.cc: Check result from ha_rnd_init() sql/ha_partition.h: Fixed compiler warning sql/handler.cc: Added ha_rnd_init_with_error() Check result from ha_rnd_init() sql/handler.h: Added ha_rnd_init_with_error() Changed prototype of ha_rnd_init() to ensure that we get a compile warning if result is not checked sql/item_subselect.cc: Check result from ha_rnd_init() sql/log.cc: Check result from ha_rnd_init() sql/log_event.cc: Check result from ha_rnd_init() sql/log_event_old.cc: Check result from ha_rnd_init() sql/mysql_priv.h: init_read_record() now returns error code on failure sql/opt_range.cc: Check result from ha_rnd_init() sql/records.cc: init_read_record() now returns error code on failure Check result from ha_rnd_init() sql/sql_acl.cc: Check result from init_read_record() sql/sql_cursor.cc: Print error if ha_rnd_init() fails sql/sql_delete.cc: Check result from init_read_record() sql/sql_help.cc: Check result from init_read_record() sql/sql_plugin.cc: Check result from init_read_record() sql/sql_select.cc: Check result from ha_rnd_init() Print error if ha_rnd_init() fails. sql/sql_servers.cc: Check result from init_read_record() sql/sql_table.cc: Check result from init_read_record() sql/sql_udf.cc: Check result from init_read_record() sql/sql_update.cc: Check result from init_read_record() storage/example/ha_example.cc: Don't return error on rnd_init() storage/ibmdb2i/ha_ibmdb2i.cc: Removed not relevant comment
-
unknown authored
1. Changed the lazy optimization for subqueries that can be materialized into bottom-up optimization during the optimization of the main query. The main change is implemented by the method Item_in_subselect::setup_engine. All other changes were required to correct problems resulting from changing the order of optimization. Most of these problems followed the same pattern - there are some shared structures between a subquery and its parent query. Depending on which one is optimized first (parent or child query), these shared strucutres may get different values, thus resulting in an inconsistent query plan. 2. Changed the code-generation for subquery materialization to be performed in runtime memory for each (re)execution, instead of in statement memory (once per prepared statement). - Item_in_subselect::setup_engine() no longer creates materialization related objects in statement memory. - Merged subselect_hash_sj_engine::init_permanent and subselect_hash_sj_engine::init_runtime into subselect_hash_sj_engine::init, which is called for each (re)execution. - Fixed deletion of the temp table accordingly. mysql-test/r/subselect_mat.result: Adjusted changed EXPLAIN because of earlier optimization of subqueries.
-
Michael Widenius authored
Improved speed of thr_alarm from O(N) to O(1). thr_alarm is used to handle timeouts and kill of connections. Fixed compiler warnings. queues.h and queues.c are now based on the UNIREG code and thus made BSD. Fix code to use new queue() interface. This mostly affects how you access elements in the queue. If USE_NET_CLEAR is not set, don't clear connection from unexpected characters. This should give a speed up when doing a lot of fast queries. Fixed some code in ma_ft_boolean_search.c that had not made it from myisam/ft_boolean_search.c include/queues.h: Use UNIREG code base (BSD) Changed init_queue() to take all initialization arguments. New interface to access elements in queue include/thr_alarm.h: Changed to use time_t instead of ulong (portability) Added index_in_queue, to be able to remove random element from queue in O(1) mysys/queues.c: Use UNIREG code base (BSD) init_queue() and reinit_queue() now takes more initialization arguments. (No need for init_queue_ex() anymore) Now one can tell queue_insert() to store in the element a pointer to where element is in queue. This allows one to remove elements from queue in O(1) instead of O(N) mysys/thr_alarm.c: Use new option in queue() to allow fast removal of elements. Do less inside LOCK_alarm mutex. This should give a major speed up of thr_alarm usage when there is many threads sql/create_options.cc: Fixed wrong printf sql/event_queue.cc: Use new queue interface() sql/filesort.cc: Use new queue interface() sql/ha_partition.cc: Use new queue interface() sql/ha_partition.h: Fixed compiler warning sql/item_cmpfunc.cc: Fixed compiler warning sql/item_subselect.cc: Use new queue interface() Removed not used variable sql/net_serv.cc: If USE_NET_CLEAR is not set, don't clear connection from unexpected characters. This should give a speed up when doing a lot of fast queries at the disadvantage that if there is a bug in the client protocol the connection will be dropped instead of being unnoticed. sql/opt_range.cc: Use new queue interface() Fixed compiler warnings sql/uniques.cc: Use new queue interface() storage/maria/ma_ft_boolean_search.c: Copy code from myisam/ft_boolean_search.c Use new queue interface() storage/maria/ma_ft_nlq_search.c: Use new queue interface() storage/maria/ma_sort.c: Use new queue interface() storage/maria/maria_pack.c: Use new queue interface() Use queue_fix() instead of own loop to fix queue. storage/myisam/ft_boolean_search.c: Use new queue interface() storage/myisam/ft_nlq_search.c: Use new queue interface() storage/myisam/mi_test_all.sh: Remove temporary file from last run storage/myisam/myisampack.c: Use new queue interface() Use queue_fix() instead of own loop to fix queue. storage/myisam/sort.c: Use new queue interface() storage/myisammrg/myrg_queue.c: Use new queue interface() storage/myisammrg/myrg_rnext.c: Use new queue interface() storage/myisammrg/myrg_rnext_same.c: Use new queue interface() storage/myisammrg/myrg_rprev.c: Use new queue interface()
-
- 15 Jul, 2010 1 commit
-
-
unknown authored
subquery execution, where the the REF buffer format was mistaken to be in record format instead of key format. The error was that the null byte for all fields of the record was in the front of the buffer, and not before each field data.
-
- 10 Jul, 2010 1 commit
-
-
unknown authored
libmysqld/Makefile.am: The new file added. mysql-test/r/index_merge_myisam.result: subquery_cache optimization option added. mysql-test/r/myisam_mrr.result: subquery_cache optimization option added. mysql-test/r/subquery_cache.result: The subquery cache tests added. mysql-test/r/subselect3.result: Subquery cache switched off to avoid changing read statistics. mysql-test/r/subselect3_jcl6.result: Subquery cache switched off to avoid changing read statistics. mysql-test/r/subselect_no_mat.result: subquery_cache optimization option added. mysql-test/r/subselect_no_opts.result: subquery_cache optimization option added. mysql-test/r/subselect_no_semijoin.result: subquery_cache optimization option added. mysql-test/r/subselect_sj.result: subquery_cache optimization option added. mysql-test/r/subselect_sj_jcl6.result: subquery_cache optimization option added. mysql-test/t/subquery_cache.test: The subquery cache tests added. mysql-test/t/subselect3.test: Subquery cache switched off to avoid changing read statistics. sql/CMakeLists.txt: The new file added. sql/Makefile.am: The new files added. sql/item.cc: Expression cache item (Item_cache_wrapper) added. Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP. sql/item.h: Expression cache item (Item_cache_wrapper) added. Item_ref and Item_field fixed for correct usage of result field and fast resolwing in SP. sql/item_cmpfunc.cc: Subquery cache added. sql/item_cmpfunc.h: Subquery cache added. sql/item_subselect.cc: Subquery cache added. sql/item_subselect.h: Subquery cache added. sql/item_sum.cc: Registration of subquery parameters added. sql/mysql_priv.h: subquery_cache optimization option added. sql/mysqld.cc: subquery_cache optimization option added. sql/opt_range.cc: Fix due to subquery cache. sql/opt_subselect.cc: Parameters of the function cahnged. sql/procedure.h: .h file guard added. sql/sql_base.cc: Registration of subquery parameters added. sql/sql_class.cc: Option to allow add indeces to temporary table. sql/sql_class.h: Item iterators added. Option to allow add indeces to temporary table. sql/sql_expression_cache.cc: Expression cache for caching subqueries added. sql/sql_expression_cache.h: Expression cache for caching subqueries added. sql/sql_lex.cc: Registration of subquery parameters added. sql/sql_lex.h: Registration of subqueries and subquery parameters added. sql/sql_select.cc: Subquery cache added. sql/sql_select.h: Subquery cache added. sql/sql_union.cc: A new parameter to the function added. sql/sql_update.cc: A new parameter to the function added. sql/table.cc: Procedures to manage temporarty tables index added. sql/table.h: Procedures to manage temporarty tables index added. storage/maria/ha_maria.cc: Fix of handler to allow destoy a table in case of error during the table creation. storage/maria/ha_maria.h: .h file guard added. storage/myisam/ha_myisam.cc: Fix of handler to allow destoy a table in case of error during the table creation.
-
- 06 Jul, 2010 1 commit
-
-
Sergey Petrunya authored
- Item_in_subselect::init_left_expr_cache() should not try to guess whether the left expression is accessed "over the grouping operation" (i.e. the subselect is evaluated after the grouping while the left_expr is an Item_ref that wraps an expression from before the grouping). Instead, let new_Cached_item not to try accessing item->real_item() when creating left expr cache.
-
- 10 Jun, 2010 1 commit
-
-
Davi Arnaut authored
strict aliasing violations. One somewhat major source of strict-aliasing violations and related warnings is the SQL_LIST structure. For example, consider its member function `link_in_list` which takes a pointer to pointer of type T (any type) as a pointer to pointer to unsigned char. Dereferencing this pointer, which is done to reset the next field, violates strict-aliasing rules and might cause problems for surrounding code that uses the next field of the object being added to the list. The solution is to use templates to parametrize the SQL_LIST structure in order to deference the pointers with compatible types. As a side bonus, it becomes possible to remove quite a few casts related to acessing data members of SQL_LIST. sql/handler.h: Use the appropriate template type argument. sql/item.cc: Remove now-unnecessary cast. sql/item_subselect.cc: Remove now-unnecessary casts. sql/item_sum.cc: Use the appropriate template type argument. Remove now-unnecessary cast. sql/mysql_priv.h: Move SQL_LIST structure to sql_list.h Use the appropriate template type argument. sql/sp.cc: Remove now-unnecessary casts. sql/sql_delete.cc: Use the appropriate template type argument. Remove now-unnecessary casts. sql/sql_derived.cc: Remove now-unnecessary casts. sql/sql_lex.cc: Remove now-unnecessary casts. sql/sql_lex.h: SQL_LIST now takes a template type argument which must match the type of the elements of the list. Use forward declaration when the type is not available, it is used in pointers anyway. sql/sql_list.h: Rename SQL_LIST to SQL_I_List. The template parameter is the type of object that is stored in the list. sql/sql_olap.cc: Remove now-unnecessary casts. sql/sql_parse.cc: Remove now-unnecessary casts. sql/sql_prepare.cc: Remove now-unnecessary casts. sql/sql_select.cc: Remove now-unnecessary casts. sql/sql_show.cc: Remove now-unnecessary casts. sql/sql_table.cc: Remove now-unnecessary casts. sql/sql_trigger.cc: Remove now-unnecessary casts. sql/sql_union.cc: Remove now-unnecessary casts. sql/sql_update.cc: Remove now-unnecessary casts. sql/sql_view.cc: Remove now-unnecessary casts. sql/sql_yacc.yy: Remove now-unnecessary casts. storage/myisammrg/ha_myisammrg.cc: Remove now-unnecessary casts.
-
- 06 Apr, 2010 1 commit
-
-
Sergey Glukhov authored
We should disable const subselect item evaluation because subselect transformation does not happen in view_prepare_mode and thus val_...() methods can not be called. mysql-test/r/ctype_ucs.result: test case mysql-test/r/view.result: test case mysql-test/t/ctype_ucs.test: test case mysql-test/t/view.test: test case sql/item.cc: disabled const subselect item evaluation in view prepare mode. sql/item_subselect.cc: added Item_subselect::safe_charset_converter which prevents const item evaluation in view prepare mode. sql/item_subselect.h: added Item_subselect::safe_charset_converter which prevents const item evaluation in view prepare mode.
-
- 29 Mar, 2010 1 commit
-
-
Sergey Petrunya authored
- Add Item_in_subselect::get_identifier() that returns subquery's id - Change select_describe() to produce output in new format - Update test results (checked)
-
- 09 Mar, 2010 2 commits
-
-
unknown authored
query: - When subquery is located in ORDER BY, EXPLAIN will run as follows: select_describe() will run JOIN::prepare()/optimize() for the subquery; then at some point subselect_single_select_engine::prepare() will be called, which will create another join and run join->prepare(). In mainline mysql this is not a problem because subquery's join will be destroyed after the first call. In MariaDB, it won't (table elimination needs to keep JOIN objects around for longer in order to know which tables were eliminated when constructing EXPLAIN EXTENDED warning). Fix the problem of memory leak by calling select_lex->cleanup() in subselect_single_select_engine::prepare().
-
unknown authored
Bug#46949: memory leak with failed alter table to create partitions based on extract() Bug#51830: Incorrect partition pruning on range partition (regression) Fixed valgrind failure in select_describe(), read of uninitialized Item_subselect::eliminated. PBXT test file updates to reflect changes done in MySQL. mysql-test/suite/pbxt/r/partition_error.result: Result file update following MySQL 5.1.44 changes. mysql-test/suite/pbxt/r/partition_pruning.result: Result file update following MySQL 5.1.44 changes. mysql-test/suite/pbxt/t/partition_error.test: Test file update following MySQL 5.1.44 changes. sql/item_subselect.cc: Fixed valgrind failure in select_describe(), read of uninitialized Item_subselect::eliminated: - it turns out we can call select_describe() without having fixed subquery items for child subselects. These are not the kind of subqueries that we could eliminate, so the fix is to ensure that item_subselect->eliminated==FALSE even before fix_fields is called. Also added code to reset item_subselect->eliminated back to FALSE in Item::reset() call. sql/item_subselect.h: Fixed valgrind failure in select_describe(), read of uninitialized Item_subselect::eliminated: - it turns out we can call select_describe() without having fixed subquery items for child subselects. These are not the kind of subqueries that we could eliminate, so the fix is to ensure that item_subselect->eliminated==FALSE even before fix_fields is called. Also added code to reset item_subselect->eliminated back to FALSE in Item::reset() call. sql/sql_partition.cc: Fix Bug#51830: Revert part of the patch for Bug#49742, which caused the regression. sql/table.cc: Fix Bug#46949: memory leak in failed ALTER TABLE with partitioning.
-