mariadb

Tree: b1e377997e

Author	SHA1	Message	Date
Varun Gupta	b1e377997e	Fixed a typo	6 years ago
Varun Gupta	29b13d114e	Followup fix for MDEV-20440	6 years ago
Sergei Petrunia	ef76f81c98	MDEV-20109: Optimizer ignores distinct key created for materialized... (Backported to 10.3, addressed review input) Sj_materialization_picker::check_qep(): fix error in cost/fanout calculations: - for each join prefix, add #prefix_rows / TIME_FOR_COMPARE to the cost, like best_extension_by_limited_search does - Remove the fanout produced by the subquery tables. - Also take into account join condition selectivity optimize_wo_join_buffering() (used by LooseScan and FirstMatch) - also add #prefix_rows / TIME_FOR_COMPARE to the cost of each prefix. - Also take into account join condition selectivity	6 years ago
Sergei Petrunia	4a490d1a99	MDEV-6111: Optimizer Trace: add tracing for semi-join optimizations Added: - "semijoin_strategy_choice" element (actions in advance_sj_state(), name matches the name in MySQL) - semijoin_table_pullout element.	6 years ago
Igor Babaev	0955462d0a	MDEV-18479 Assertion `join->best_read < double(1.79769313486231570815e+308L)' or server crashes in JOIN::fix_all_splittings_in_plan after EXPLAIN This patch resolves the problem of overflowing when performing calculations to estimate the cost of an evaluated query execution plan. The overflowing in a non-debug build could cause different kind of problems uncluding crashes of the server.	7 years ago
Igor Babaev	2c9844a438	MDEV-18896 Crash in convert_join_subqueries_to_semijoins : Correction This patch complements the original patch for MDEV-18896 that prevents conversions to semi-joins in tableless selects used in INSERT statements in post-5.5 versions of the server. The test case was corrected as well to ensure that potential conversion to jtbm semi-joins is also checked (the problem was that one of the preceeding testcases in subselect_sj.test did not restore the state of the optimizer switch leaving the 'materialization' in the state 'off' and so blocking this check). Noticed an inconsistency in the state of select_lex::table_list used in INSERT statements and left a comment about this.	7 years ago
Sergei Petrunia	b1f828a82a	MDEV-19134: EXISTS() slower if ORDER BY is defined Step 1: Removal of ORDER BY [LIMIT] from the subquery should be done earlier and for broader class of subqueries. The rewrite was done in Item_in_subselect::select_in_like_transformer(), but this had problems: - It didn't cover EXISTS subqueries - It covered IN-subqueries, but was done after the semi-join transformation was considered inapplicable, because ORDER BY was present. Remaining issue: - EXISTS->IN transformation happens before check_and_do_in_subquery_rewrites() is called, so it is still prevented by the present ORDER BY.	7 years ago
Michal Schorm	17b4f99928	Update FSF address This commit is based on the work of Michal Schorm, rebased on the earliest MariaDB version. Th command line used to generate this diff was: find ./ -type f \ -exec sed -i -e 's/Foundation, Inc., 59 Temple Place, Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \ -exec sed -i -e 's/Foundation, Inc. 59 Temple Place.* Suite 330, Boston, /Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, /g' {} \; \ -exec sed -i -e 's/MA......-1307.USA/MA 02110-1335 USA/g' {} \; \ -exec sed -i -e 's/Foundation, Inc., 59 Temple/Foundation, Inc., 51 Franklin/g' {} \; \ -exec sed -i -e 's/Place, Suite 330, Boston, MA.02111-1307.USA/Street, Fifth Floor, Boston, MA 02110-1335 USA/g' {} \; \ -exec sed -i -e 's/MA.*.....-1307/MA 02110-1335/g' {} \;	7 years ago
Vladislav Vaintroub	ad36d38024	MDEV-19235 MariaDB Server compiled for 128 Indexes crashes at startup With MAX_INDEXIES=64(default), key_map=Bitmap<64> is just a wrapper around ulonglong and thus "trivial" (can be bzero-ed, or memcpy-ed, and stays valid still) With MAX_INDEXES=128, key_map = Bitmap<128> is not a "trivial" type anymore. The implementation uses MY_BITMAP, and MY_BITMAP contains pointers which make Bitmap invalid, when it is memcpy-ed/bzero-ed. The problem in 10.4 is that there are many new key_map members, inside TABLE or KEY, and those are often memcopied and bzeroed The fix makes Bitmap "trivial", by inlining most of MY_BITMAP functionality. pointers/heap allocations are not used anymore.	7 years ago
Galina Shalygina	a765b19e5c	MDEV-19245: Impossible WHERE should be noticed earlier after HAVING pushdown The bug appears because not all conditions are found to be knowingly true or false in WHERE after HAVING pushdown optimization. Impossible WHERE can be found much earlier compared with how it is done now. To fix it and_new_conditions_to_optimized_cond() is changed.	7 years ago
Galina Shalygina	ae15f91f22	MDEV-18769 Assertion `fixed == 1' failed in Item_cond_or::val_int This bug is caused by pushdown from HAVING into WHERE. It appears because condition that is pushed wasn't fixed. It is also discovered that condition pushdown from HAVING into WHERE is done wrong. There is no need to build clones for some conditions that can be pushed. They can be simply moved from HAVING into WHERE without cloning. build_pushable_cond_for_having_pushdown(), remove_pushed_top_conjuncts_for_having() methods are changed. It is found that there is no transformation made for fields of pushed condition. field_transformer_for_having_pushdown transformer is added. New tests are added. Some comments are changed.	7 years ago
Igor Babaev	0dd12b4f2a	MDEV-18896 Crash in convert_join_subqueries_to_semijoins If an IN-subquery is used in a table-less select the current code should never consider it as candidate for semi-join optimizations. Yet the function check_and_do_in_subquery_rewrites() improperly checked the property "to be a table-less select". As a result such select in IN subquery was used in INSERT .. SELECT then the IN subquery by mistake was registered as a semi-join subquery and convert_subq_to_sj() was called for it. However the code of this function does not assume that the parent select of the subquery could be a table-less select.	7 years ago
Igor Babaev	8283d7d2c0	MDEV-7486: Condition pushdown from HAVING into WHERE Optimized the code that removed multiple equalities pushed from HAVING into WHERE. Now this removal is postponed until all multiple equalities are eliminated in substitute_for_best_equal_field().	7 years ago
Galina Shalygina	d25af33116	MDEV-18635 The test case for bug mdev-16727 crashes the server in the tree bb-10.4-mdev7486 The crash was caused because after merge of bb-10.4-mdev7486 and 10.4 branches changes for mdev-16727 were missing.	7 years ago
Varun Gupta	9cb55143ac	Minor cleanup in the optimizer trace code. More test coverage added for the optimizer trace.	7 years ago
Galina Shalygina	7a77b221f1	MDEV-7486: Condition pushdown from HAVING into WHERE Condition can be pushed from the HAVING clause into the WHERE clause if it depends only on the fields that are used in the GROUP BY list or depends on the fields that are equal to grouping fields. Aggregate functions can't be pushed down. How the pushdown is performed on the example: SELECT t1.a,MAX(t1.b) FROM t1 GROUP BY t1.a HAVING (t1.a>2) AND (MAX(c)>12); => SELECT t1.a,MAX(t1.b) FROM t1 WHERE (t1.a>2) GROUP BY t1.a HAVING (MAX(c)>12); The implementation scheme: 1. Extract the most restrictive condition cond from the HAVING clause of the select that depends only on the fields that are used in the GROUP BY list of the select (directly or indirectly through equalities) 2. Save cond as a condition that can be pushed into the WHERE clause of the select 3. Remove cond from the HAVING clause if it is possible The optimization is implemented in the function st_select_lex::pushdown_from_having_into_where(). New test file having_cond_pushdown.test is created.	8 years ago
Varun Gupta	be8709eb7b	MDEV-6111 Optimizer Trace This task involves the implementation for the optimizer trace. This feature produces a trace for any SELECT/UPDATE/DELETE/, which contains information about decisions taken by the optimizer during the optimization phase (choice of table access method, various costs, transformations, etc). This feature would help to tell why some decisions were taken by the optimizer and why some were rejected. Trace is session-local, controlled by the @@optimizer_trace variable. To enable optimizer trace we need to write: set @@optimizer_trace variable= 'enabled=on'; To display the trace one can run: SELECT trace FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE; This task also involves: MDEV-18489: Limit the memory used by the optimizer trace introduces a switch optimizer_trace_max_mem_size which limits the memory used by the optimizer trace. This was implemented by Sergei Petrunia.	7 years ago
Igor Babaev	13e217b8c1	MDEV-17027 server crashes in Bitmap<64u>::merge The function and_new_conditions_to_optimized_cond() incorrectly handled the WHERE conditions with one multiple equality and one IN subquery predicate that could be converted into a jtbm semi-join. This could cause crashes. The fix code was prepared by Galina Shalygina.	7 years ago
Igor Babaev	d03581bf3c	MDEV-17360 Server crashes in optimize_keyuse This was a bug in the code of MDEV-12387 "Push conditions into materialized subqueries". The bug manifested itself in rather rare situations. An affected query must contain IN subquery predicate whose left operand was an outer field of a mergeable derived table or view and right operand was a materialized subquery. The erroneous code in fact stripped off the Item_direct_ref wrapper from the left operand of the IN subquery predicate when building equalities produced by the conversion of the predicate into a semi-join. As a result the left operand was not considered as an outer reference anymore and used_tables() was calculated incorrectly. This caused a crash in the function optimize_keyuse().	7 years ago
Oleksandr Byelkin	701f0b8e36	Fix gcc 7.3 compiler warnings.	7 years ago
Galina Shalygina	af46c25760	MDEV-16727: Server crashes in Item_equal_iterator<List_iterator_fast, Item>::get_curr_field() The bug appeares because of the lamely saved list of multiple equalities. To fix it and_new_conditions_to_optimized_cond() was changed.	7 years ago
Galina Shalygina	aee3d162d2	MDEV-16730: Server crashes in Bitmap<64u>::merge The problem appears because of the pushdown of a non-pushable condition 'cond' into the materialized derived table/view. To prevent pushdown a map of tables that are used in 'cond' should be updated. This call is missing because of the MDEV-12387 changes. The call is added in the setup_jtbm_semi_joins() method.	7 years ago
Galina Shalygina	2a3d3e052f	MDEV-16721: Assertion `ctx.compare_type_handler()->cmp_type() != STRING_RESULT' failed The bug appeared as in MDEV-12387 setup_jtbm_semi_joins() procedure had been devided into two functions, one called before optimization of WHERE clause and another after this optimization. When the second function was called for a degenerated jtbm semi join equalities connecting the subselect and the parent select were created but invocation of fix_fields() for these equalities was missing.	7 years ago
Varun Gupta	37dee22d27	MDEV-15454: Nested SELECT IN returns wrong results In this case we are setting the field Item_func_eq::in_eqaulity_no for the semi-join equalities. This helps us to remove these equalites as the inner tables are not available during parent select execution while the outer tables are not available during materialization phase. We only have it set for the equalites for the fields involved with the IN subquery and reset it for the equalities which do not belong to the IN subquery. For example in case of nested IN subqueries: SELECT t1.a FROM t1 WHERE t1.a IN (SELECT t2.a FROM t2 where t2.b IN (select t3.b from t3 where t3.c=27 )) there are two equalites involving the fields of the IN subquery 1) t2.b = t3.b : the field Item_func_eq::in_eqaulity_no is set when we merge the grandchild select into the child select 2) t1.a = t2.a : the field Item_func_eq::in_eqaulity_no is set when we merge the child select into the parent select But when we perform case 2) we should ensure that we reset the equalities in the child's WHERE clause.	7 years ago
Varun Gupta	f9b43c2565	MDEV-16751: Server crashes in st_join_table::cleanup or TABLE_LIST::is_with_table_recursive_reference with join_cache_level>2 During muliple equality propagation for a query in which we have an IN subquery, the items in the select list of the subquery may not be part of the multiple equality because there might be another occurence of the same field in the where clause of the subquery. So we keyuse_is_valid_for_access_in_chosen_plan function which expects the items in the select list of the subquery to be same to the ones in the multiple equality (through these multiple equalities we create keyuse array). The solution would be that we expect the same field not the same Item because when we have SEMI JOIN MATERIALIZATION SCAN, we use copy back technique to copies back the materialised table fields to the original fields of the base tables.	7 years ago
Sergei Petrunia	2fbf2277ff	MDEV-15982: Incorrect results when subquery is materialized fix_semijoin_strategies_for_picked_join_order() should set join->sjm_lookup_tables to be a bitmap of tables inside SJ-Materialization-Lookup nests.	7 years ago
Oleksandr Byelkin	de745ecf29	MDEV-11953: support of brackets in UNION/EXCEPT/INTERSECT operations	8 years ago
Igor Babaev	147744d455	MDEV-16235 Server crashes in my_utf8_uni or in my_strtod_int upon SELECT .. LIMIT 0 (new variant) This is another attempt to fix the problem of mdev-14515.	8 years ago
Alexander Barkov	f4dfc609cf	MDEV-16388 Replace member Item::fixed to virtual method is_fixed()	8 years ago
Alexander Barkov	106f0b5798	MDEV-16385 ROW SP variable is allowed in unexpected context The problem described in the bug report happened because the code did not test check_cols(1) after fix_fields() in a few places. Additionally, fix_fields() could be called multiple times for SP variables, because they are all fixed at a early stage in append_for_log(). Solution: 1. Adding a few helper methods - fix_fields_if_needed() - fix_fields_if_needed_for_scalar() - fix_fields_if_needed_for_bool() - fix_fields_if_needed_for_order_by() and using it in many cases instead of fix_fields() where the "fixed" status is not definitely known to be "false". 2. Adding DBUG_ASSERT(!fixed) into Item_splocal*::fix_fields() to catch double execution. 3. Adding tests. As a good side effect, the patch removes a lot of duplicate code (~60 lines): if (!item->fixed && item->fix_fields(..) && item->check_cols(1)) return true;	8 years ago
Galina Shalygina	d3ff133390	MDEV-12387 Push conditions into materialized subqueries The logic and the implementation scheme are similar with the MDEV-9197 Pushdown conditions into non-mergeable views/derived tables How the push down is made on the example: select * from t1 where a>3 and b>10 and (a,b) in (select x,max(y) from t2 group by x); --> select * from t1 where a>3 and b>10 and (a,b) in (select x,max(y) from t2 where x>3 group by x having max(y)>10); The implementation scheme: 1. Search for the condition cond that depends only on the fields from the left part of the IN subquery (left_part) 2. Find fields F_group in the select of the right part of the IN subquery (right_part) that are used in the GROUP BY 3. Extract from the cond condition cond_where that depends only on the fields from the left_part that stay at the same places in the left_part (have the same indexes) as the F_group fields in the projection of the right_part 4. Transform cond_where so it can be pushed into the WHERE clause of the right_part and delete cond_where from the cond 5. Transform cond so it can be pushed into the HAVING clause of the right_part The optimization is made in the Item_in_subselect::pushdown_cond_for_in_subquery() and is controlled by the variable condition_pushdown_for_subquery. New test file in_subq_cond_pushdown.test is created. There are also some changes made for setup_jtbm_semi_joins(). Now it is decomposed into the 2 procedures: setup_degenerate_jtbm_semi_joins() that is called before optimize_cond() for cond and setup_jtbm_semi_joins() that is called after optimize_cond(). New setup_jtbm_semi_joins() is made in the way so that the result of its work is the same as if it was called before optimize_cond(). The code that is common for pushdown into materialized derived and into materialized IN subqueries is factored out into pushdown_cond_for_derived(), Item_in_subselect::pushdown_cond_for_in_subquery() and st_select_lex::pushdown_cond_into_where_clause().	8 years ago
Galina Shalygina	8b26fea835	MDEV-16088: Pushdown into materialized views/derived tables doesn't work in the IN subqueries The pushdown into the materialized derived table/view wasn't done because optimize() for the derived was called before any conditions that can be pushed down were extracted. So optimize() in convert_join_subqueries_to_semijoins() method is called too early and is unnecessary. The second optimize() call in mysql_handle_single_derived() is enough.	8 years ago
Monty	30ebc3ee9e	Add likely/unlikely to speed up execution Added to: - if (error) - Lex - sql_yacc.yy and sql_yacc_ora.yy - In header files to alloc() calls - Added thd argument to thd_net_is_killed()	8 years ago
Oleksandr Byelkin	adaa891ae7	MDEV-13699: Assertion `!new_field->field_name.str \|\| strlen(new_field->field_name.str) == new_field->field_name.length' failed in create_tmp_table on 2nd execution of PS with semijoin The problem was that SJ (semi-join) used secondary list (array) of subquery select list. The items there was prepared once then cleaned up (but not really freed from memory because it was made in statement memory). Original list was not prepared after first execution because select was removed by conversion to SJ. The solution is to use original list but prepare it first.	8 years ago
Igor Babaev	5e61e1716e	MDEV-14515 ifnull result depends on number of rows in joined table Any expensive WHERE condition for a table-less query with implicit aggregation was lost. As a result the used aggregate functions were calculated over a non-empty set of rows even in the case when the condition was false.	8 years ago
Varun Gupta	ddc5c65333	MDEV-14779: using left join causes incorrect results with materialization and derived tables Conversion of a subquery to a semi-join is blocked when we have an IN subquery predicate in the on_expr of an outer join. Currently this scenario is handled but the cases when an IN subquery predicate is wrapped inside a Item_in_optimizer item then this blocking is not done.	8 years ago
Varun Gupta	926edd48e1	MDEV-15235: Assertion `length > 0' failed in create_ref_for_key The issue is that we are creating a materialised table with key of length 0 which is incorrect, we should disable materialisation for such a case.	8 years ago
Monty	d69642dedd	Added name to MEM_ROOT for esier debugging This will make it easier to how memory allocation is done when debugging with either DBUG or gdb. Will especially help when debugging stored procedures Main change is a name argument as second argument to init_alloc_root() init_sql_alloc() Other things: - Added DBUG_ENTER/EXIT to some Virtual_tmp_table functions	8 years ago
Monty	a7e352b54d	Changed database, tablename and alias to be LEX_CSTRING This was done in, among other things: - thd->db and thd->db_length - TABLE_LIST tablename, db, alias and schema_name - Audit plugin database name - lex->db - All db and table names in Alter_table_ctx - st_select_lex db Other things: - Changed a lot of functions to take const LEX_CSTRING* as argument for db, table_name and alias. See init_one_table() as an example. - Changed some function arguments from LEX_CSTRING to const LEX_CSTRING - Changed some lists from LEX_STRING to LEX_CSTRING - threads_mysql.result changed because process list_db wasn't always correctly updated - New append_identifier() function that takes LEX_CSTRING* as arguments - Added new element tmp_buff to Alter_table_ctx to separate temp name handling from temporary space - Ensure we store the length after my_casedn_str() of table/db names - Removed not used version of rename_table_in_stat_tables() - Changed Natural_join_column::table_name and db_name() to never return NULL (used for print) - thd->get_db() now returns db as a printable string (thd->db.str or "")	8 years ago
Monty	95f3933944	Fixed compiler warnings Only warnings, should not have caused any bugs in old code	8 years ago
Oleksandr Byelkin	9c9cf556a1	MDEV-13933: Wrong results in COUNT() query with EXISTS and exists_to_in Roll back to most general duplicate removing strategi in case of different stratagies for one position.	8 years ago
Igor Babaev	4f0299f8b3	This is a full cost-based implementation of the optimization that employs splitting technique for equi-joins of materialized derived tables/views/CTEs. (see mdev-13369 and mdev-13389).	8 years ago
Alexander Barkov	590400f743	MDEV-14517 Cleanup for Item::with_subselect and Item::has_subquery()	8 years ago
Michael Widenius	87933d5261	Handle failures from malloc Most "new" failures fixed in the following files: - sql_select.cc - item.cc - item_func.cc - opt_subselect.cc Other things: - Allocate udf_handler strings in mem_root - Required changes in sql_string.h - Add mem_root as argument to some new [] calls - Mark udf_handler strings as thread specific - Removed some comment blocks with code	8 years ago
Oleksandr Byelkin	c2c93fc6e4	MDEV-14164: Unknown column error when adding aggregate to function in oracle style procedure FOR loop Make differentiation between pullout for merge and pulout of outer field during exists2in transformation. In last case the field was outer and so we can safely start from name resolution context of the SELECT where it was pulled. Old behavior lead to inconsistence between list of tables and outer name resolution context (which skips one SELECT for merge purposes) which creates problem vor name resolution.	8 years ago
Oleksandr Byelkin	235b68299b	MDEV-9619: Assertion `null_ref_table' failed in virtual table_map Item_direct_view_ref::used_tables() const on 2nd execution of PS Refer left expression indirectly in case it changes from execution to execution.	9 years ago
Galina Shalygina	6bce8e1422	Post review changes for the optimization of IN predicates into IN subqueries.	8 years ago
Eugene Kosov	5dd8e1bf2d	simplify READ_RECORD usage NFC READ_RECORD read_record; ... // this // read_record.read_record(&read_record); // becomes just read_record.read_record();	8 years ago
Galina Shalygina	570d2e7d0f	Summarized results of two previous commits (26 July, 25 August)	8 years ago
Michael Widenius	cc77f9882d	Changed KEY names to use LEX_CSTRING	9 years ago

1 2 3 4 5 ...

482 Commits (b1e377997e987b66c999713bdb7e6cfdb87797ae)