set optimizer_trace_max_mem_size=1048576; set end_markers_in_json=on; set optimizer_trace="enabled=on"; # check that if a sub-statement should not be traced, # it is not traced even if inside a traced top statement set optimizer_trace_offset=0, optimizer_trace_limit=100; create function f1(arg char(1)) returns int begin declare res int; declare dummy varchar(1); select 1 into res from dual; select TRACE+NULL into dummy from information_schema.OPTIMIZER_TRACE limit 1; select 2 into res from dual; return 3; end| select f1("c")| f1("c") 3 select * from information_schema.OPTIMIZER_TRACE| QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select f1("c") { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `f1`('c') AS `f1(\"c\")`" } ] /* steps */ } /* join_preparation */ } ] /* steps */ } 0 0 select f1("c") { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `f1`('c') AS `f1(\"c\")`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 set res@1 NULL { "steps": [ ] /* steps */ } 0 0 set dummy@2 NULL { "steps": [ ] /* steps */ } 0 0 select 1 into res from dual { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select 1 AS `1`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 select 2 into res from dual { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select 2 AS `2`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 freturn 3 3 { "steps": [ ] /* steps */ } 0 0 set optimizer_trace_offset=default, optimizer_trace_limit=default; drop function f1; # check that if a tracing gets disabled in a routine's body, # substatements are not traced set optimizer_trace_offset=0, optimizer_trace_limit=100; create function f1(arg char(1)) returns int begin declare res int; declare dummy varchar(1); set optimizer_trace="enabled=off"; select 1 into res from dual; select TRACE+NULL into dummy from information_schema.OPTIMIZER_TRACE limit 1; select 2 into res from dual; return 3; end| select f1("c")| f1("c") 3 select * from information_schema.OPTIMIZER_TRACE| QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select f1("c") { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `f1`('c') AS `f1(\"c\")`" } ] /* steps */ } /* join_preparation */ } ] /* steps */ } 0 0 select f1("c") { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `f1`('c') AS `f1(\"c\")`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 set res@1 NULL { "steps": [ ] /* steps */ } 0 0 set dummy@2 NULL { "steps": [ ] /* steps */ } 0 0 set optimizer_trace_offset=default, optimizer_trace_limit=default; select @@optimizer_trace; @@optimizer_trace enabled=off,one_line=off set optimizer_trace="enabled=on"; drop function f1; # Check that if a sub-statement reads OPTIMIZER_TRACE, # thus reading the unfinished trace of its caller statement, # there is no crash. create temporary table optt (id int primary key auto_increment, QUERY varchar(200), TRACE text); create table t1 (a int, key(a)); insert into t1 values(2); set optimizer_trace_offset=0, optimizer_trace_limit=100; create function f1(arg char(1)) returns int begin declare res int; insert into optt select NULL, QUERY, TRACE from information_schema.OPTIMIZER_TRACE; return 3; end| select * from t1 where a in (select f1("c") from t1)| a set optimizer_trace="enabled=off"; this should find unfinished traces select count(*) from optt where TRACE NOT LIKE "%] /* steps */\n}"; count(*) 1 select count(*)<>0 from optt; count(*)<>0 1 this should not select count(*) from information_schema.OPTIMIZER_TRACE where TRACE NOT LIKE "%] /* steps */\n}"; count(*) 0 select count(*)<>0 from information_schema.OPTIMIZER_TRACE; count(*)<>0 1 set optimizer_trace_offset=default, optimizer_trace_limit=default; drop temporary table optt; drop function f1; drop table t1; set optimizer_trace="enabled=on"; # check of crash with I_S.VIEWS (TABLE_LIST::alias==NULL) create table t1(a int, b int); create view v1 as select a from t1; select VIEW_DEFINITION from information_schema.VIEWS where TABLE_SCHEMA="test" and TABLE_NAME="v1"; VIEW_DEFINITION select `test`.`t1`.`a` AS `a` from `test`.`t1` drop table t1; drop view v1; # check for readable display of BIT values create table t1 (a bit(5), key(a)); insert into t1 values(b'00000'),(b'01101'); select cast(a as unsigned) from t1 where a > b'01100'; cast(a as unsigned) 13 select TRACE from information_schema.OPTIMIZER_TRACE; TRACE { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select cast(`t1`.`a` as unsigned) AS `cast(a as unsigned)` from `t1` where (`t1`.`a` > 0x0c)" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(`t1`.`a` > 0x0c)", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(`t1`.`a` > 0x0c)" }, { "transformation": "constant_propagation", "resulting_condition": "(`t1`.`a` > 0x0c)" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(`t1`.`a` > 0x0c)" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "range_analysis": { "table_scan": { "rows": 2, "cost": 4.5034 } /* table_scan */, "potential_range_indexes": [ { "index": "a", "usable": true, "key_parts": [ "a" ] /* key_parts */ } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "a", "cost": 1.4175, "chosen": true } /* best_covering_index_scan */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_group_by_or_distinct" } /* group_index_range */, "analyzing_range_alternatives": { "range_scan_alternatives": [ { "index": "a", "ranges": [ "12 < a" ] /* ranges */, "index_dives_for_eq_ranges": true, "rowid_ordered": false, "using_mrr": false, "index_only": true, "rows": 2, "cost": 1.4275, "chosen": false, "cause": "cost" } ] /* range_scan_alternatives */, "analyzing_roworder_intersect": { "usable": false, "cause": "too_few_roworder_scans" } /* analyzing_roworder_intersect */ } /* analyzing_range_alternatives */ } /* range_analysis */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4034, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4034, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "(`t1`.`a` > 0x0c)", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": "(`t1`.`a` > 0x0c)" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } drop table t1; # check that trace lists all pushed down ON conditions create table t1 (i int not null); insert into t1 values (0), (2),(3),(4); create table t2 (i int not null); insert into t2 values (0),(1), (3),(4); create table t3 (i int not null); insert into t3 values (0),(1),(2), (4); select * from t1 LEFT JOIN ( t2 LEFT JOIN ( t3 ) ON t3.i = t2.i ) ON t2.i = t1.i WHERE t3.i IS NULL ; i i i 3 3 NULL 2 NULL NULL select TRACE from information_schema.OPTIMIZER_TRACE; TRACE { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `t1`.`i` AS `i`,`t2`.`i` AS `i`,`t3`.`i` AS `i` from `t1` left join (`t2` left join `t3` on((`t3`.`i` = `t2`.`i`))) on((`t2`.`i` = `t1`.`i`)) where isnull(`t3`.`i`)" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "isnull(`t3`.`i`)", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "isnull(`t3`.`i`)" }, { "transformation": "constant_propagation", "resulting_condition": "isnull(`t3`.`i`)" }, { "transformation": "trivial_condition_removal", "resulting_condition": "isnull(`t3`.`i`)" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t2`", "row_may_be_null": true, "map_bit": 1, "depends_on_map_bits": [ 0 ] /* depends_on_map_bits */ }, { "table": "`t3`", "row_may_be_null": true, "map_bit": 2, "depends_on_map_bits": [ 0, 1 ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 4, "cost": 2 } /* table_scan */ }, { "table": "`t2`", "table_scan": { "rows": 4, "cost": 2 } /* table_scan */ }, { "table": "`t3`", "table_scan": { "rows": 4, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 4, "access_type": "scan", "resulting_rows": 4, "cost": 2.8068, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 4, "cost_for_plan": 2.8068, "rest_of_plan": [ { "plan_prefix": [ "`t1`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 4, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 4, "cost": 5.207, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 16, "cost_for_plan": 8.0138, "rest_of_plan": [ { "plan_prefix": [ "`t1`", "`t2`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 4, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 1, "cost": 5.8083, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 16, "cost_for_plan": 13.822, "chosen": true } ] /* rest_of_plan */ } ] /* rest_of_plan */ } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "isnull(`t3`.`i`)", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": null }, { "table": "`t2`", "attached": "(is_not_null_compl(t2..t3), (`t2`.`i` = `t1`.`i`), true)" }, { "table": "`t3`", "attached": "((found_match(t2..t3), (found_match(t3), isnull(`t3`.`i`), true), true) and (is_not_null_compl(t3), (`t3`.`i` = `t1`.`i`), true))" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" }, { "table": "`t2`" }, { "table": "`t3`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } drop table t1,t2,t3; # test of tracing a query with an HAVING condition, in # ps-protocol, does not crash CREATE TABLE t1 (f1 INT, f2 VARCHAR(1)); INSERT INTO t1 VALUES (16,'f'); INSERT INTO t1 VALUES (16,'f'); CREATE TABLE t2 (f1 INT, f2 VARCHAR(1)); INSERT INTO t2 VALUES (13,'f'); INSERT INTO t2 VALUES (20,'f'); CREATE TABLE t3 (f1 INT, f2 VARCHAR(1)); INSERT INTO t3 VALUES (7,'f'); EXPLAIN SELECT t1.f2 FROM t1 STRAIGHT_JOIN (t2 JOIN t3 ON t3.f2 = t2.f2 ) ON t3 .f2 = t2 .f2 HAVING ('v', 'i') NOT IN (SELECT f2, MIN(f2) FROM t1) ORDER BY f2; id select_type table partitions type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t1 NULL ALL NULL NULL NULL NULL 2 100.00 Using temporary; Using filesort 1 PRIMARY t3 NULL ALL NULL NULL NULL NULL 1 100.00 Using join buffer (Block Nested Loop) 1 PRIMARY t2 NULL ALL NULL NULL NULL NULL 2 50.00 Using where; Using join buffer (Block Nested Loop) 2 SUBQUERY t1 NULL ALL NULL NULL NULL NULL 2 100.00 NULL Warnings: Note 1003 /* select#1 */ select `test`.`t1`.`f2` AS `f2` from `test`.`t1` join `test`.`t2` join `test`.`t3` where (`test`.`t2`.`f2` = `test`.`t3`.`f2`) having (not(((('v','i')),(/* select#2 */ select 1,1 from `test`.`t1` having (((('v') = `test`.`t1`.`f2`) or isnull(`test`.`t1`.`f2`)) and ((('i') = min(`test`.`t1`.`f2`)) or isnull(min(`test`.`t1`.`f2`))) and (`test`.`t1`.`f2`) and (min(`test`.`t1`.`f2`))))))) order by `test`.`t1`.`f2` SELECT t1.f2 FROM t1 STRAIGHT_JOIN (t2 JOIN t3 ON t3.f2 = t2.f2 ) ON t3 .f2 = t2 .f2 HAVING ('v', 'i') NOT IN (SELECT f2, MIN(f2) FROM t1) ORDER BY f2; f2 f f f f select TRACE from information_schema.OPTIMIZER_TRACE; TRACE { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))" }, { "transformation": { "select#": 2, "from": "IN (SELECT)", "to": "semijoin", "chosen": false } /* transformation */ } ] /* steps */ } /* join_preparation */ }, { "expanded_query": "/* select#1 */ select `t1`.`f2` AS `f2` from `t1` join `t2` join `t3` where ((`t3`.`f2` = `t2`.`f2`) and (`t3`.`f2` = `t2`.`f2`)) having (not((('v','i'),(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`))))))) order by `t1`.`f2`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "((`t3`.`f2` = `t2`.`f2`) and (`t3`.`f2` = `t2`.`f2`))", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(multiple equal(`t3`.`f2`, `t2`.`f2`))" }, { "transformation": "constant_propagation", "resulting_condition": "(multiple equal(`t3`.`f2`, `t2`.`f2`))" }, { "transformation": "trivial_condition_removal", "resulting_condition": "multiple equal(`t3`.`f2`, `t2`.`f2`)" } ] /* steps */ } /* condition_processing */ }, { "condition_processing": { "condition": "HAVING", "original_condition": "(not((('v','i'),(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))))))", "steps": [ { "transformation": "constant_propagation", "subselect_evaluation": [ ] /* subselect_evaluation */, "resulting_condition": "(not((('v','i'),(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))))))" }, { "transformation": "trivial_condition_removal", "subselect_evaluation": [ ] /* subselect_evaluation */, "resulting_condition": "(not((('v','i'),(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))))))" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t2`", "row_may_be_null": false, "map_bit": 1, "depends_on_map_bits": [ 0 ] /* depends_on_map_bits */ }, { "table": "`t3`", "row_may_be_null": false, "map_bit": 2, "depends_on_map_bits": [ 0 ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ }, { "table": "`t2`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ }, { "table": "`t3`", "table_scan": { "rows": 1, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4098, "chosen": true, "use_tmp_table": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4098, "rest_of_plan": [ { "plan_prefix": [ "`t1`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 1, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 1, "cost": 2.4049, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 4.8147, "rest_of_plan": [ { "plan_prefix": [ "`t1`", "`t3`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 2, "cost": 2.8099, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 4, "cost_for_plan": 7.6246, "sort_cost": 4, "new_cost_for_plan": 11.625, "chosen": true } ] /* rest_of_plan */ }, { "plan_prefix": [ "`t1`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 2, "cost": 2.8098, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 4, "cost_for_plan": 5.2196, "pruned_by_heuristic": true } ] /* rest_of_plan */ } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "(`t2`.`f2` = `t3`.`f2`)", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": null }, { "table": "`t3`", "attached": null }, { "table": "`t2`", "attached": "(`t2`.`f2` = `t3`.`f2`)" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "clause_processing": { "clause": "ORDER BY", "original_clause": "`t1`.`f2`", "items": [ { "item": "`t1`.`f2`" } ] /* items */, "resulting_clause_is_simple": true, "resulting_clause": "`t1`.`f2`" } /* clause_processing */ }, { "refine_plan": [ { "table": "`t1`" }, { "table": "`t3`" }, { "table": "`t2`" } ] /* refine_plan */ }, { "sort_using_internal_table": { "condition_for_sort": "(not(((('v','i')),(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))))))", "having_after_sort": null } /* sort_using_internal_table */ } ] /* steps */ } /* join_optimization */ }, { "join_optimization": { "select#": 2, "steps": [ { "condition_processing": { "condition": "HAVING", "original_condition": "(((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))", "steps": [ { "transformation": "constant_propagation", "resulting_condition": "(((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(((('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and (`t1`.`f2`) and (min(`t1`.`f2`)))" } ] /* steps */ } /* condition_processing */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4098, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4098, "chosen": true } ] /* considered_execution_plans */ }, { "transformation": { "select#": 2, "from": "IN (SELECT)", "to": "materialization", "has_nullable_expressions": true, "treat_UNKNOWN_as_FALSE": false, "possible": false, "cause": "cannot_handle_partial_matches" } /* transformation */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ { "creating_tmp_table": { "tmp_table_info": { "table": "intermediate_tmp_table", "row_length": 3, "key_length": 0, "unique_constraint": false, "location": "memory (heap)", "row_limit_estimate": 349525 } /* tmp_table_info */ } /* creating_tmp_table */ }, { "filesort_information": [ { "direction": "asc", "table": "intermediate_tmp_table", "field": "f2" } ] /* filesort_information */, "filesort_priority_queue_optimization": { "usable": false, "cause": "not applicable (no LIMIT)" } /* filesort_priority_queue_optimization */, "filesort_execution": [ { "subselect_execution": { "select#": 2, "steps": [ { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ }, { "subselect_execution": { "select#": 2, "steps": [ ] /* steps */ } /* subselect_execution */ }, { "subselect_execution": { "select#": 2, "steps": [ ] /* steps */ } /* subselect_execution */ }, { "subselect_execution": { "select#": 2, "steps": [ ] /* steps */ } /* subselect_execution */ } ] /* filesort_execution */, "filesort_summary": { "rows": 4, "examined_rows": 4, "number_of_tmp_files": 0, "sort_buffer_size": "NNN", "sort_mode": "" } /* filesort_summary */ } ] /* steps */ } /* join_execution */ } ] /* steps */ } DROP TABLES t1,t2,t3; # Test that tracing a query with a materialized FROM-clause # derived table using a GROUP BY, does not crash create table t1 (a int, b int); insert into t1 values (1,1), (2,null), (3, 4); select max(x) from (select sum(a) as x from t1 group by b) as teeone; max(x) 3 select TRACE from information_schema.OPTIMIZER_TRACE; TRACE { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select sum(`t1`.`a`) AS `x` from `t1` group by `t1`.`b`" } ] /* steps */ } /* join_preparation */ }, { "derived": { "table": " `teeone`", "select#": 2, "materialized": true } /* derived */ }, { "expanded_query": "/* select#1 */ select max(`teeone`.`x`) AS `max(x)` from (/* select#2 */ select sum(`t1`.`a`) AS `x` from `t1` group by `t1`.`b`) `teeone`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "join_optimization": { "select#": 2, "steps": [ { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 3, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 3, "access_type": "scan", "resulting_rows": 3, "cost": 2.6066, "chosen": true, "use_tmp_table": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 3, "cost_for_plan": 2.6066, "sort_cost": 3, "new_cost_for_plan": 5.6066, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "clause_processing": { "clause": "GROUP BY", "original_clause": "`t1`.`b`", "items": [ { "item": "`t1`.`b`" } ] /* items */, "resulting_clause_is_simple": true, "resulting_clause": "`t1`.`b`" } /* clause_processing */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "table_dependencies": [ { "table": " `teeone`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": " `teeone`", "table_scan": { "rows": 3, "cost": 10 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": " `teeone`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 3, "access_type": "scan", "resulting_rows": 3, "cost": 10.75, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 3, "cost_for_plan": 10.75, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": " `teeone`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": " `teeone`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ { "creating_tmp_table": { "tmp_table_info": { "table": " `teeone`", "row_length": 16, "key_length": 0, "unique_constraint": false, "location": "memory (heap)", "row_limit_estimate": 65536 } /* tmp_table_info */ } /* creating_tmp_table */ }, { "join_execution": { "select#": 2, "steps": [ { "creating_tmp_table": { "tmp_table_info": { "table": "intermediate_tmp_table", "row_length": 22, "key_length": 5, "unique_constraint": false, "location": "memory (heap)", "row_limit_estimate": 47662 } /* tmp_table_info */ } /* creating_tmp_table */ }, { "filesort_information": [ { "direction": "asc", "table": "intermediate_tmp_table", "field": "b" } ] /* filesort_information */, "filesort_priority_queue_optimization": { "usable": false, "cause": "not applicable (no LIMIT)" } /* filesort_priority_queue_optimization */, "filesort_execution": [ ] /* filesort_execution */, "filesort_summary": { "rows": 3, "examined_rows": 3, "number_of_tmp_files": 0, "sort_buffer_size": "NNN", "sort_mode": "" } /* filesort_summary */ } ] /* steps */ } /* join_execution */ } ] /* steps */ } /* join_execution */ } ] /* steps */ } drop table t1; # To have no crash above, we had to restore the ref_array at # end of JOIN::exec(). This impacts how the query looks like, # but not too much, as seen in the error message below. # Comes from func_gconcat.test. CREATE TABLE t1(f1 int); INSERT INTO t1 values (0),(0); set optimizer_trace="enabled=off"; SELECT POLYGON((SELECT 1 FROM (SELECT 1 IN (GROUP_CONCAT(t1.f1)) FROM t1, t1 t GROUP BY t.f1 ) d)); ERROR 22007: Illegal non geometric '(select 1 from (select (1 = group_concat(`test`.`t1`.`f1` separator ',')) AS `1 IN (GROUP_CONCAT(t1.f1))` from `test`.`t1` join `test`.`t1` `t` group by `test`.`t`.`f1`) `d`)' value found during parsing set optimizer_trace="enabled=on"; SELECT POLYGON((SELECT 1 FROM (SELECT 1 IN (GROUP_CONCAT(t1.f1)) FROM t1, t1 t GROUP BY t.f1 ) d)); ERROR 22007: Illegal non geometric '(select 1 from (select (1 = group_concat(`test`.`t1`.`f1` separator ',')) AS `1 IN (GROUP_CONCAT(t1.f1))` from `test`.`t1` join `test`.`t1` `t` group by `test`.`t`.`f1`) `d`)' value found during parsing DROP TABLE t1; # Check that SQL PREPARE and SQL EXECUTE each produce one trace. set optimizer_trace_offset=0, optimizer_trace_limit=100; prepare stmt from "select 1"; select * from information_schema.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select 1 { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select 1 AS `1`" } ] /* steps */ } /* join_preparation */ } ] /* steps */ } 0 0 set optimizer_trace_offset=0, optimizer_trace_limit=100; execute stmt; 1 1 select * from information_schema.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select 1 { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select 1 AS `1`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 deallocate prepare stmt; set optimizer_trace_offset=default, optimizer_trace_limit=default; # Test of SELECTs in IF in stored routine. # Same test for CASE WHEN. create table t1 (a int); create procedure p1() begin if exists(select 1) then insert into t1 values(1); end if; if exists(select 2) then insert into t1 values(2); end if; if (select count(*) from t1) then insert into t1 values(3); end if; set @a=(select count(a) from t1 where a>0); case (select count(a) from t1 where a>1) when 2 then set @b=2; else set @b=3; end case; end| set optimizer_trace_offset=0, optimizer_trace_limit=100; set @old_max=@@optimizer_trace_max_mem_size; set optimizer_trace_max_mem_size=40000; call p1(); select * from information_schema.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES set @old_max=@@optimizer_trace_max_mem_size { "steps": [ ] /* steps */ } 0 0 set optimizer_trace_max_mem_size=40000 { "steps": [ ] /* steps */ } 0 0 call p1() { "steps": [ ] /* steps */ } 0 0 jump_if_not 2(2) exists(select 1) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select 1" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 insert into t1 values(1) { "steps": [ ] /* steps */ } 0 0 jump_if_not 4(4) exists(select 2) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select 2" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 insert into t1 values(2) { "steps": [ ] /* steps */ } 0 0 jump_if_not 6(6) (select count(0) from `test`.`t1`) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select count(0) from `t1`" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ ] /* steps */, "empty_result": { "cause": "Select tables optimized away" } /* empty_result */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 insert into t1 values(3) { "steps": [ ] /* steps */ } 0 0 SET @a=(select count(a) from t1 where a>0) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select count(`t1`.`a`) from `t1` where (`t1`.`a` > 0)" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(`t1`.`a` > 0)", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(`t1`.`a` > 0)" }, { "transformation": "constant_propagation", "resulting_condition": "(`t1`.`a` > 0)" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(`t1`.`a` > 0)" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 3, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 3, "access_type": "scan", "resulting_rows": 1, "cost": 2.6051, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 2.6051, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "(`t1`.`a` > 0)", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": "(`t1`.`a` > 0)" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 set_case_expr (15) 0 (select count(`a`) from `test`.`t1` where (`a` > 1)) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select count(`t1`.`a`) from `t1` where (`t1`.`a` > 1)" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(`t1`.`a` > 1)", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(`t1`.`a` > 1)" }, { "transformation": "constant_propagation", "resulting_condition": "(`t1`.`a` > 1)" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(`t1`.`a` > 1)" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 3, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 3, "access_type": "scan", "resulting_rows": 1, "cost": 2.6051, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 2.6051, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "(`t1`.`a` > 1)", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": "(`t1`.`a` > 1)" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 jump_if_not_case_when 11(15) (case_expr@0 = 2) { "steps": [ ] /* steps */ } 0 0 SET @b=2 { "steps": [ ] /* steps */ } 0 0 select * from t1; a 1 2 3 select @a,@b; @a @b 3 2 set optimizer_trace_max_mem_size=@old_max; drop procedure p1; drop table t1; # Test of tracing of DO. set optimizer_trace_offset=0, optimizer_trace_limit=100; do (select 42); select * from information_schema.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES do (select 42) { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select 42" } ] /* steps */ } /* join_preparation */ }, { "expanded_query": "/* select#1 */ select (/* select#2 */ select 42) AS `(select 42)`" } ] /* steps */ } /* join_preparation */ } ] /* steps */ } 0 0 do (select 42) { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select 42" } ] /* steps */ } /* join_preparation */ }, { "expanded_query": "/* select#1 */ select (/* select#2 */ select 42) AS `(select 42)`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_optimization": { "select#": 2, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ { "subselect_execution": { "select#": 2, "steps": [ { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 # Test of tracing of subquery used in parameter of routine call create table t1(a int); insert into t1 values(1),(2); create procedure p1(x int) begin declare b int; set b=(select 2+x from dual); end| set optimizer_trace_offset=0, optimizer_trace_limit=100; call p1((select a from t1 limit 1)); select * from information_schema.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES call p1((select a from t1 limit 1)) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select `t1`.`a` from `t1` limit 1" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4034, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4034, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 set b@1 NULL { "steps": [ ] /* steps */ } 0 0 set b@1 (select (2 + x@0)) { "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select (2 + x@0)" } ] /* steps */ } /* join_preparation */ }, { "subselect_execution": { "select#": 2, "steps": [ { "join_optimization": { "select#": 2, "steps": [ ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* subselect_execution */ } ] /* steps */ } 0 0 drop procedure p1; drop table t1; set optimizer_trace_offset=default, optimizer_trace_limit=default; # Test that printing expanded query does not alter query's # results. # Comes from ctype_utf8mb4_heap.test create table t1 (f1 varchar(1) not null) default charset utf8mb4; insert into t1 values (''), (''); select concat(concat(_latin1'->',f1),_latin1'<-') from t1; concat(concat(_latin1'->',f1),_latin1'<-') -><- -><- select * from information_schema.optimizer_trace; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select concat(concat(_latin1'->',f1),_latin1'<-') from t1 { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select concat(concat('->',`t1`.`f1`),'<-') AS `concat(concat(_latin1'->',f1),_latin1'<-')` from `t1`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4098, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4098, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 drop table t1; # Bug#12546331 - SEGFAULT IN SUBSELECT_INDEXSUBQUERY_ENGINE::PRINT WITH OPTIMIZER TRACE CREATE TABLE t1 ( col_int_nokey INT, col_int_key INT, col_varchar_key varchar(1), KEY col_int_key (col_int_key), KEY col_varchar_key (col_varchar_key,col_int_key) ); INSERT INTO t1 VALUES (NULL,8,'x'), (8,7,'d'), (1,1,'r'), (9,7,'f'), (4,9,'y'), (3,NULL,'u'), (2,1,'m'), (NULL,9,NULL), (2,2,'o'), (NULL,9,'w'), (6,2,'m'), (7,4,'q'), (2,0,NULL), (5,4,'d'), (7,8,'g'), (6,NULL,'x'), (6,NULL,'f'), (2,0,'p'), (9,NULL,'j'), (6,8,'c') ; CREATE TABLE t2 ( col_int_nokey INT, col_int_key INT, col_varchar_key varchar(1), KEY col_int_key (col_int_key), KEY col_varchar_key (col_varchar_key,col_int_key) ); INSERT INTO t2 VALUES (2,4,'v'), (150,62,'v'), (NULL,7,'c'), (2,1,NULL), (5,0,'x'), (3,7,'i'), (1,7,'e'), (4,1,'p'), (NULL,7,'s'), (2,1,'j'), (6,5,'z'), (6,2,'c'), (8,0,'a'), (2,1,'q'), (6,8,'y'), (8,1,NULL), (3,1,'r'), (3,9,'v'), (9,1,NULL), (6,5,'r') ; SELECT col_int_nokey FROM ( SELECT * FROM t2 WHERE col_varchar_key > 'a' OR ( 7 , 5 ) NOT IN ( SELECT col_int_nokey , col_int_key FROM t1 ) ) AS alias1; col_int_nokey 2 150 NULL 2 5 3 1 4 NULL 2 6 6 8 2 6 8 3 3 9 6 DROP TABLE t1; DROP TABLE t2; BUG#12552262 - INVALID JSON WITH TWO CALLS TO TEST_QUICK_SELECT CREATE TABLE t1 ( col_varchar_10_latin1_key varchar(10) DEFAULT NULL, col_int_key INT, KEY col_int_key (col_int_key) ); CREATE TABLE t2 ( col_varchar_10_latin1_key varchar(10) DEFAULT NULL, col_varchar_10_utf8_key varchar(10) CHARACTER SET utf8 DEFAULT NULL, col_int_key INT, KEY col_varchar_10_utf8_key (col_varchar_10_utf8_key), KEY col_int_key (col_int_key) ); INSERT INTO t2 VALUES ('qykbaqfyhz','l',NULL); CREATE TABLE t3 ( col_int_key INT, col_varchar_10_utf8_key varchar(10) CHARACTER SET utf8 DEFAULT NULL, col_varchar_10_latin1_key varchar(10) DEFAULT NULL, KEY col_varchar_10_utf8_key (col_varchar_10_utf8_key), KEY col_varchar_10_latin1_key (col_varchar_10_latin1_key) ); INSERT INTO t3 VALUES (0,'s','it'); INSERT INTO t3 VALUES (9,'IQTHK','JCAQM'); SELECT table2.col_int_key FROM t3 AS table1 LEFT JOIN t1 AS table2 ON table1.col_int_key < table2.col_int_key LEFT JOIN t2 AS table3 ON table2.col_varchar_10_latin1_key >= table3.col_varchar_10_utf8_key ; col_int_key NULL NULL select * from information_schema.optimizer_trace; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES SELECT table2.col_int_key FROM t3 AS table1 LEFT JOIN t1 AS table2 ON table1.col_int_key < table2.col_int_key LEFT JOIN t2 AS table3 ON table2.col_varchar_10_latin1_key >= table3.col_varchar_10_utf8_key { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `table2`.`col_int_key` AS `col_int_key` from `t3` `table1` left join `t1` `table2` on((`table1`.`col_int_key` < `table2`.`col_int_key`)) left join `t2` `table3` on((convert(`table2`.`col_varchar_10_latin1_key` using utf8) >= `table3`.`col_varchar_10_utf8_key`))" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": null, "steps": [ { "transformation": "equality_propagation", "resulting_condition": null } ] /* steps */ } /* condition_processing */ }, { "table_dependencies": [ { "table": "`t3` `table1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t1` `table2`", "row_may_be_null": true, "map_bit": 1, "depends_on_map_bits": [ 0 ] /* depends_on_map_bits */ }, { "table": "`t2` `table3`", "row_may_be_null": true, "map_bit": 2, "depends_on_map_bits": [ 0, 1 ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t3` `table1`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ }, { "table": "`t1` `table2`", "rows": 1, "cost": 1, "table_type": "system", "empty": true }, { "table": "`t2` `table3`", "table_scan": { "rows": 1, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ "`t1` `table2`" ] /* plan_prefix */, "table": "`t3` `table1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4107, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4107, "rest_of_plan": [ { "plan_prefix": [ "`t1` `table2`", "`t3` `table1`" ] /* plan_prefix */, "table": "`t2` `table3`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 1, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 1, "cost": 2.405, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 4.8157, "chosen": true } ] /* rest_of_plan */ } ] /* considered_execution_plans */ }, { "condition_on_constant_tables": "1", "condition_value": true }, { "attaching_conditions_to_tables": { "original_condition": "1", "attached_conditions_computation": [ { "table": "`t2` `table3`", "rechecking_index_usage": { "recheck_reason": "not_first_table", "range_analysis": { "table_scan": { "rows": 1, "cost": 4.3049 } /* table_scan */, "potential_range_indexes": [ { "index": "col_varchar_10_utf8_key", "usable": true, "key_parts": [ "col_varchar_10_utf8_key" ] /* key_parts */ }, { "index": "col_int_key", "usable": false, "cause": "not_applicable" } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "col_varchar_10_utf8_key", "cost": 1.2, "chosen": true } /* best_covering_index_scan */, "setup_range_conditions": [ { "impossible_condition": { "cause": "comparison_with_null_always_false" } /* impossible_condition */ } ] /* setup_range_conditions */, "impossible_range": true } /* range_analysis */, "without_ON_clause": { "range_analysis": { "table_scan": { "rows": 1, "cost": 4.3049 } /* table_scan */, "potential_range_indexes": [ { "index": "col_varchar_10_utf8_key", "usable": true, "key_parts": [ "col_varchar_10_utf8_key" ] /* key_parts */ }, { "index": "col_int_key", "usable": false, "cause": "not_applicable" } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "col_varchar_10_utf8_key", "cost": 1.2, "chosen": true } /* best_covering_index_scan */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */ } /* range_analysis */ } /* without_ON_clause */ } /* rechecking_index_usage */ } ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t3` `table1`", "attached": null }, { "table": "`t2` `table3`", "attached": "(is_not_null_compl(table3), (convert(NULL using utf8) >= `table3`.`col_varchar_10_utf8_key`), true)" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t3` `table1`" }, { "table": "`t2` `table3`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 DROP TABLE t1,t2,t3; Tests of tracing of the "eq_ref optimization" of plan search create table t0 (a int); insert into t0 values (0),(1),(2),(3),(4),(5),(6),(7),(8),(9); create table t1 (a int, b int, key(a)); create table t2 (a int, b int, key(a)); create table t3 (a int, b int, key(a)); insert into t1 select a,a from t0; insert into t2 select a,a from t0; insert into t3 select a,a from t0; set @old_opt_switch=@@optimizer_switch; explain select * from t0 where a in (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a); id select_type table partitions type possible_keys key key_len ref rows filtered Extra 1 PRIMARY t0 NULL ALL NULL NULL NULL NULL 10 100.00 Using where 2 DEPENDENT SUBQUERY t1 NULL index a a 5 NULL 10 100.00 Using where; Using index 2 DEPENDENT SUBQUERY t2 NULL ref a a 5 test.t1.a 1 100.00 Using index 2 DEPENDENT SUBQUERY t3 NULL ref a a 5 test.t1.a 1 100.00 Using index Warnings: Note 1003 /* select#1 */ select `test`.`t0`.`a` AS `a` from `test`.`t0` where (`test`.`t0`.`a`,(/* select#2 */ select 1 from `test`.`t1` join `test`.`t2` join `test`.`t3` where ((`test`.`t2`.`a` = `test`.`t1`.`a`) and (`test`.`t3`.`a` = `test`.`t1`.`a`) and ((`test`.`t0`.`a`) = (`test`.`t1`.`a` + `test`.`t1`.`a`))))) select * from information_schema.optimizer_trace; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES explain select * from t0 where a in (select t2.a+t3.a from t1 left join (t2 join t3) on t2.a=t1.a and t3.a=t1.a) { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select (`t2`.`a` + `t3`.`a`) from (`t1` left join (`t2` join `t3`) on(((`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))" }, { "transformation": { "select#": 2, "from": "IN (SELECT)", "to": "semijoin", "chosen": false } /* transformation */ }, { "transformation": { "select#": 2, "from": "IN (SELECT)", "to": "EXISTS (CORRELATED SELECT)", "chosen": true, "evaluating_constant_where_conditions": [ ] /* evaluating_constant_where_conditions */ } /* transformation */ } ] /* steps */ } /* join_preparation */ }, { "expanded_query": "/* select#1 */ select `t0`.`a` AS `a` from `t0` where (`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from (`t1` left join (`t2` join `t3`) on(((`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`)))) where ((`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))" }, { "transformations_to_nested_joins": { "transformations": [ "outer_join_to_inner_join", "JOIN_condition_to_WHERE", "parenthesis_removal" ] /* transformations */, "expanded_query": "/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))" } /* transformations_to_nested_joins */ } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))", "steps": [ { "transformation": "equality_propagation", "subselect_evaluation": [ ] /* subselect_evaluation */, "resulting_condition": "(`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))" }, { "transformation": "constant_propagation", "subselect_evaluation": [ ] /* subselect_evaluation */, "resulting_condition": "(`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))" }, { "transformation": "trivial_condition_removal", "subselect_evaluation": [ ] /* subselect_evaluation */, "resulting_condition": "(`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t0`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t0`", "table_scan": { "rows": 10, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t0`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 10, "access_type": "scan", "resulting_rows": 10, "cost": 4.0171, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 4.0171, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "(`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t0`", "attached": "(`t0`.`a`,(/* select#2 */ select (`t2`.`a` + `t3`.`a`) from `t1` join `t2` join `t3` where (((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))))" } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t0`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_optimization": { "select#": 2, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and multiple equal(`t2`.`a`, `t1`.`a`, `t3`.`a`))" }, { "transformation": "constant_propagation", "resulting_condition": "(((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and multiple equal(`t2`.`a`, `t1`.`a`, `t3`.`a`))" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(((`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and multiple equal(`t2`.`a`, `t1`.`a`, `t3`.`a`))" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t2`", "row_may_be_null": true, "map_bit": 1, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t3`", "row_may_be_null": true, "map_bit": 2, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ { "table": "`t1`", "field": "a", "equals": "`t2`.`a`", "null_rejecting": true }, { "table": "`t1`", "field": "a", "equals": "`t3`.`a`", "null_rejecting": true }, { "table": "`t2`", "field": "a", "equals": "`t1`.`a`", "null_rejecting": true }, { "table": "`t2`", "field": "a", "equals": "`t3`.`a`", "null_rejecting": true }, { "table": "`t3`", "field": "a", "equals": "`t2`.`a`", "null_rejecting": true }, { "table": "`t3`", "field": "a", "equals": "`t1`.`a`", "null_rejecting": true } ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 10, "cost": 2 } /* table_scan */ }, { "table": "`t2`", "table_scan": { "rows": 10, "cost": 2 } /* table_scan */ }, { "table": "`t3`", "table_scan": { "rows": 10, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "usable": false, "chosen": false }, { "rows_to_scan": 10, "access_type": "scan", "resulting_rows": 10, "cost": 4.022, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 4.022, "rest_of_plan": [ { "plan_prefix": [ "`t1`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.022, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 16.022, "rest_of_plan": [ { "plan_prefix": [ "`t1`", "`t2`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.023, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 28.022, "chosen": true } ] /* rest_of_plan */ } ] /* rest_of_plan */ }, { "plan_prefix": [ ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "usable": false, "chosen": false }, { "rows_to_scan": 10, "access_type": "scan", "resulting_rows": 10, "cost": 4.022, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 4.022, "rest_of_plan": [ { "plan_prefix": [ "`t2`" ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.022, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 16.022, "rest_of_plan": [ { "plan_prefix": [ "`t2`", "`t1`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.023, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 28.022, "pruned_by_cost": true }, { "plan_prefix": [ "`t2`", "`t1`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.023, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 28.022, "pruned_by_cost": true } ] /* rest_of_plan */ }, { "plan_prefix": [ "`t2`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.022, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 16.022, "pruned_by_heuristic": true } ] /* rest_of_plan */ }, { "plan_prefix": [ ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "usable": false, "chosen": false }, { "rows_to_scan": 10, "access_type": "scan", "resulting_rows": 10, "cost": 4.022, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 4.022, "rest_of_plan": [ { "plan_prefix": [ "`t3`" ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.022, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 16.022, "rest_of_plan": [ { "plan_prefix": [ "`t3`", "`t1`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.023, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 28.022, "pruned_by_cost": true }, { "plan_prefix": [ "`t3`", "`t1`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.023, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 28.022, "pruned_by_cost": true } ] /* rest_of_plan */ }, { "plan_prefix": [ "`t3`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "a", "rows": 1, "cost": 12, "chosen": true }, { "rows_to_scan": 10, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 10, "cost": 22.022, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 10, "cost_for_plan": 16.022, "pruned_by_heuristic": true } ] /* rest_of_plan */ } ] /* considered_execution_plans */ }, { "transformation": { "select#": 2, "from": "IN (SELECT)", "to": "EXISTS (CORRELATED SELECT)", "put_1_in_SELECT_list": true } /* transformation */ }, { "attaching_conditions_to_tables": { "original_condition": "((`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`) and ((`t0`.`a`) = (`t1`.`a` + `t1`.`a`)))", "attached_conditions_computation": [ { "table": "`t1`", "rechecking_index_usage": { "recheck_reason": "not_first_table", "range_analysis": { "table_scan": { "rows": 10, "cost": 14 } /* table_scan */, "potential_range_indexes": [ { "index": "a", "usable": true, "key_parts": [ "a" ] /* key_parts */ } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "a", "cost": 3.2093, "chosen": true } /* best_covering_index_scan */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */ } /* range_analysis */ } /* rechecking_index_usage */ } ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1`", "attached": "((`t0`.`a`) = (`t1`.`a` + `t1`.`a`))" }, { "table": "`t2`", "attached": null }, { "table": "`t3`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`t1`" }, { "table": "`t2`" }, { "table": "`t3`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_explain": { "select#": 1, "steps": [ { "join_explain": { "select#": 2, "steps": [ ] /* steps */ } /* join_explain */ } ] /* steps */ } /* join_explain */ } ] /* steps */ } 0 0 set optimizer_switch=@old_opt_switch; drop table t0,t1,t2,t3; CREATE TABLE t1 ( OBJECTID int(11) NOT NULL default '0', SORTORDER int(11) NOT NULL auto_increment, KEY t1_SortIndex (SORTORDER), KEY t1_IdIndex (OBJECTID) ) ENGINE=MyISAM DEFAULT CHARSET=latin1; CREATE TABLE t2 ( ID int(11) default NULL, PARID int(11) default NULL, UNIQUE KEY t2_ID_IDX (ID), KEY t2_PARID_IDX (PARID) ) engine=MyISAM DEFAULT CHARSET=latin1; INSERT INTO t2 VALUES (1000,0),(1001,0),(1002,0),(1003,0),(1008,1),(1009,1),(1010,1),(1011,1),(1016,2); CREATE TABLE t3 ( ID int(11) default NULL, DATA decimal(10,2) default NULL, UNIQUE KEY t3_ID_IDX (ID) ) engine=MyISAM DEFAULT CHARSET=latin1; INSERT INTO t3 VALUES (1000,0.00),(1001,0.25),(1002,0.50),(1003,0.75),(1008,1.00),(1009,1.25),(1010,1.50),(1011,1.75); select 497, tmp.ID, NULL from (select 497 as ID, MAX(t3.DATA) as DATA from t1 join t2 on (t1.ObjectID = t2.ID) join t3 on (t1.ObjectID = t3.ID) group by t2.ParID order by DATA DESC) as tmp; 497 ID NULL select * from information_schema.optimizer_trace; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select 497, tmp.ID, NULL from (select 497 as ID, MAX(t3.DATA) as DATA from t1 join t2 on (t1.ObjectID = t2.ID) join t3 on (t1.ObjectID = t3.ID) group by t2.ParID order by DATA DESC) as tmp { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "join_preparation": { "select#": 2, "steps": [ { "expanded_query": "/* select#2 */ select 497 AS `ID`,max(`t3`.`DATA`) AS `DATA` from `t1` join `t2` join `t3` where ((`t1`.`OBJECTID` = `t3`.`ID`) and (`t1`.`OBJECTID` = `t2`.`ID`)) group by `t2`.`PARID` order by `DATA` desc" } ] /* steps */ } /* join_preparation */ }, { "derived": { "table": " `tmp`", "select#": 2, "materialized": true } /* derived */ }, { "expanded_query": "/* select#1 */ select 497 AS `497`,`tmp`.`ID` AS `ID`,NULL AS `NULL` from (/* select#2 */ select 497 AS `ID`,max(`t3`.`DATA`) AS `DATA` from `t1` join `t2` join `t3` where ((`t1`.`OBJECTID` = `t3`.`ID`) and (`t1`.`OBJECTID` = `t2`.`ID`)) group by `t2`.`PARID` order by `DATA` desc) `tmp`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "join_optimization": { "select#": 2, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "((`t1`.`OBJECTID` = `t3`.`ID`) and (`t1`.`OBJECTID` = `t2`.`ID`))", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(multiple equal(`t1`.`OBJECTID`, `t3`.`ID`, `t2`.`ID`))" }, { "transformation": "constant_propagation", "resulting_condition": "(multiple equal(`t1`.`OBJECTID`, `t3`.`ID`, `t2`.`ID`))" }, { "transformation": "trivial_condition_removal", "resulting_condition": "multiple equal(`t1`.`OBJECTID`, `t3`.`ID`, `t2`.`ID`)" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t2`", "row_may_be_null": false, "map_bit": 1, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t3`", "row_may_be_null": false, "map_bit": 2, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ { "table": "`t1`", "field": "OBJECTID", "equals": "`t3`.`ID`", "null_rejecting": true }, { "table": "`t1`", "field": "OBJECTID", "equals": "`t2`.`ID`", "null_rejecting": true }, { "table": "`t2`", "field": "ID", "equals": "`t1`.`OBJECTID`", "null_rejecting": false }, { "table": "`t2`", "field": "ID", "equals": "`t3`.`ID`", "null_rejecting": true }, { "table": "`t3`", "field": "ID", "equals": "`t1`.`OBJECTID`", "null_rejecting": false }, { "table": "`t3`", "field": "ID", "equals": "`t2`.`ID`", "null_rejecting": true } ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "rows": 1, "cost": 1, "table_type": "system", "empty": true }, { "table": "`t2`", "const_keys_added": { "keys": [ "t2_PARID_IDX" ] /* keys */, "cause": "group_by" } /* const_keys_added */, "range_analysis": { "table_scan": { "rows": 9, "cost": 5.9198 } /* table_scan */, "potential_range_indexes": [ { "index": "t2_ID_IDX", "usable": false, "cause": "not_applicable" }, { "index": "t2_PARID_IDX", "usable": true, "key_parts": [ "PARID" ] /* key_parts */ } ] /* potential_range_indexes */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */ } /* range_analysis */ }, { "table": "`t3`", "table_scan": { "rows": 8, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ "`t1`" ] /* plan_prefix */, "table": "`t3`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "t3_ID_IDX", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "scan", "cost": 3.6, "rows": 8, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 1.2, "rest_of_plan": [ { "plan_prefix": [ "`t1`", "`t3`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "t2_ID_IDX", "rows": 2, "cost": 2.4, "chosen": true }, { "access_type": "scan", "cost": 3.8, "rows": 9, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": false }, { "plan_prefix": [ "`t1`", "`t3`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "t2_ID_IDX", "rows": 2, "cost": 2.4, "chosen": true }, { "access_type": "scan", "cost": 3.8, "rows": 9, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 3.6, "chosen": true } ] /* rest_of_plan */ }, { "plan_prefix": [ "`t1`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "t2_ID_IDX", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "scan", "cost": 3.8, "rows": 9, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 1.2, "pruned_by_heuristic": true } ] /* considered_execution_plans */ } ] /* steps */, "empty_result": { "cause": "no matching row in const table" } /* empty_result */ } /* join_optimization */ }, { "table_dependencies": [ { "table": " `tmp`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": " `tmp`", "table_scan": { "rows": 2, "cost": 10 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": " `tmp`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 10.5, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 10.5, "chosen": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": " `tmp`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": " `tmp`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ { "creating_tmp_table": { "tmp_table_info": { "table": " `tmp`", "row_length": 10, "key_length": 0, "unique_constraint": false, "location": "memory (heap)", "row_limit_estimate": 104857 } /* tmp_table_info */ } /* creating_tmp_table */ }, { "join_execution": { "select#": 2, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 drop table t1,t2,t3; CREATE TABLE t1 ( t1_id bigint(21) NOT NULL auto_increment, _field_72 varchar(128) DEFAULT '' NOT NULL, _field_95 varchar(32), _field_115 tinyint(4) DEFAULT '0' NOT NULL, _field_122 tinyint(4) DEFAULT '0' NOT NULL, _field_126 tinyint(4), _field_134 tinyint(4), PRIMARY KEY (t1_id), UNIQUE _field_72 (_field_72), KEY _field_115 (_field_115), KEY _field_122 (_field_122) ); INSERT INTO t1 VALUES (1,'admin','21232f297a57a5a743894a0e4a801fc3',0,1,NULL,NULL); INSERT INTO t1 VALUES (2,'hroberts','7415275a8c95952901e42b13a6b78566',0,1,NULL,NULL); INSERT INTO t1 VALUES (3,'guest','d41d8cd98f00b204e9800998ecf8427e',1,0,NULL,NULL); CREATE TABLE t2 ( seq_0_id bigint(21) DEFAULT '0' NOT NULL, seq_1_id bigint(21) DEFAULT '0' NOT NULL, PRIMARY KEY (seq_0_id,seq_1_id) ); INSERT INTO t2 VALUES (1,1); INSERT INTO t2 VALUES (2,1); INSERT INTO t2 VALUES (2,2); SET sql_mode = 'NO_ENGINE_SUBSTITUTION'; Warnings: Warning 3090 Changing sql mode 'NO_AUTO_CREATE_USER' is deprecated. It will be removed in a future release. CREATE TABLE t3 ( t3_id bigint(21) NOT NULL auto_increment, _field_131 varchar(128), _field_133 tinyint(4) DEFAULT '0' NOT NULL, _field_135 datetime DEFAULT '0000-00-00 00:00:00' NOT NULL, _field_137 tinyint(4), _field_139 datetime DEFAULT '0000-00-00 00:00:00' NOT NULL, _field_140 blob, _field_142 tinyint(4) DEFAULT '0' NOT NULL, _field_145 tinyint(4) DEFAULT '0' NOT NULL, _field_148 tinyint(4) DEFAULT '0' NOT NULL, PRIMARY KEY (t3_id), KEY _field_133 (_field_133), KEY _field_135 (_field_135), KEY _field_139 (_field_139), KEY _field_142 (_field_142), KEY _field_145 (_field_145), KEY _field_148 (_field_148) ); INSERT INTO t3 VALUES (1,'test job 1',0,'0000-00-00 00:00:00',0,'1999-02-25 22:43:32','test\r\njob\r\n1',0,0,0); INSERT INTO t3 VALUES (2,'test job 2',0,'0000-00-00 00:00:00',0,'1999-02-26 21:08:04','',0,0,0); SET sql_mode = default; CREATE TABLE t4 ( seq_0_id bigint(21) DEFAULT '0' NOT NULL, seq_1_id bigint(21) DEFAULT '0' NOT NULL, PRIMARY KEY (seq_0_id,seq_1_id) ); INSERT INTO t4 VALUES (1,1); INSERT INTO t4 VALUES (2,1); CREATE TABLE t5 ( t5_id bigint(21) NOT NULL auto_increment, _field_149 tinyint(4), _field_156 varchar(128) DEFAULT '' NOT NULL, _field_157 varchar(128) DEFAULT '' NOT NULL, _field_158 varchar(128) DEFAULT '' NOT NULL, _field_159 varchar(128) DEFAULT '' NOT NULL, _field_160 varchar(128) DEFAULT '' NOT NULL, _field_161 varchar(128) DEFAULT '' NOT NULL, PRIMARY KEY (t5_id), KEY _field_156 (_field_156), KEY _field_157 (_field_157), KEY _field_158 (_field_158), KEY _field_159 (_field_159), KEY _field_160 (_field_160), KEY _field_161 (_field_161) ); INSERT INTO t5 VALUES (1,0,'tomato','','','','',''); INSERT INTO t5 VALUES (2,0,'cilantro','','','','',''); CREATE TABLE t6 ( seq_0_id bigint(21) DEFAULT '0' NOT NULL, seq_1_id bigint(21) DEFAULT '0' NOT NULL, PRIMARY KEY (seq_0_id,seq_1_id) ); INSERT INTO t6 VALUES (1,1); INSERT INTO t6 VALUES (1,2); INSERT INTO t6 VALUES (2,2); CREATE TABLE t7 ( t7_id bigint(21) NOT NULL auto_increment, _field_143 tinyint(4), _field_165 varchar(32), _field_166 smallint(6) DEFAULT '0' NOT NULL, PRIMARY KEY (t7_id), KEY _field_166 (_field_166) ); INSERT INTO t7 VALUES (1,0,'High',1); INSERT INTO t7 VALUES (2,0,'Medium',2); INSERT INTO t7 VALUES (3,0,'Low',3); select replace(t3._field_140, "\r","^M"), t3_id, min(t3._field_131), min(t3._field_135), min(t3._field_139), min(t3._field_137), min(link_alias_142._field_165), min(link_alias_133._field_72), min(t3._field_145), min(link_alias_148._field_156), replace(min(t3._field_140), "\r","^M"), t3.t3_id from t3 left join t4 on t4.seq_0_id = t3.t3_id left join t7 link_alias_142 on t4.seq_1_id = link_alias_142.t7_id left join t6 on t6.seq_0_id = t3.t3_id left join t1 link_alias_133 on t6.seq_1_id = link_alias_133.t1_id left join t2 on t2.seq_0_id = t3.t3_id left join t5 link_alias_148 on t2.seq_1_id = link_alias_148.t5_id where t3.t3_id in (1) group by t3.t3_id order by link_alias_142._field_166, _field_139, link_alias_133._field_72, _field_135, link_alias_148._field_156 ; replace(t3._field_140, "\r","^M") t3_id min(t3._field_131) min(t3._field_135) min(t3._field_139) min(t3._field_137) min(link_alias_142._field_165) min(link_alias_133._field_72) min(t3._field_145) min(link_alias_148._field_156) replace(min(t3._field_140), "\r","^M") t3_id test^M job^M 1 1 test job 1 0000-00-00 00:00:00 1999-02-25 22:43:32 0 High admin 0 tomato test^M job^M 1 1 select * from information_schema.optimizer_trace; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select replace(t3._field_140, "\r","^M"), t3_id, min(t3._field_131), min(t3._field_135), min(t3._field_139), min(t3._field_137), min(link_alias_142._field_165), min(link_alias_133._field_72), min(t3._field_145), min(link_alias_148._field_156), replace(min(t3._field_140), "\r","^M"), t3.t3_id from t3 left join t4 on t4.seq_0_id = t3.t3_id left join t7 link_alias_142 on t4.seq_1_id = link_alias_142.t7_id left join t6 on t6.seq_0_id = t3.t3_id left join t1 link_alias_133 on t6.seq_1_id = link_alias_133.t1_id left join t2 on t2.seq_0_id = t3.t3_id left join t5 link_alias_148 on t2.seq_1_id = link_alias_148.t5_id where t3.t3_id in (1) group by t3.t3_id order by link_alias_142._field_166, _field_139, link_alias_133._field_72, _field_135, link_alias_148._field_156 { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select replace(`t3`.`_field_140`,'\\r','^M') AS `replace(t3._field_140, \"\\r\",\"^M\")`,`t3`.`t3_id` AS `t3_id`,min(`t3`.`_field_131`) AS `min(t3._field_131)`,min(`t3`.`_field_135`) AS `min(t3._field_135)`,min(`t3`.`_field_139`) AS `min(t3._field_139)`,min(`t3`.`_field_137`) AS `min(t3._field_137)`,min(`link_alias_142`.`_field_165`) AS `min(link_alias_142._field_165)`,min(`link_alias_133`.`_field_72`) AS `min(link_alias_133._field_72)`,min(`t3`.`_field_145`) AS `min(t3._field_145)`,min(`link_alias_148`.`_field_156`) AS `min(link_alias_148._field_156)`,replace(min(`t3`.`_field_140`),'\\r','^M') AS `replace(min(t3._field_140), \"\\r\",\"^M\")`,`t3`.`t3_id` AS `t3_id` from `t3` left join `t4` on((`t4`.`seq_0_id` = `t3`.`t3_id`)) left join `t7` `link_alias_142` on((`t4`.`seq_1_id` = `link_alias_142`.`t7_id`)) left join `t6` on((`t6`.`seq_0_id` = `t3`.`t3_id`)) left join `t1` `link_alias_133` on((`t6`.`seq_1_id` = `link_alias_133`.`t1_id`)) left join `t2` on((`t2`.`seq_0_id` = `t3`.`t3_id`)) left join `t5` `link_alias_148` on((`t2`.`seq_1_id` = `link_alias_148`.`t5_id`)) where (`t3`.`t3_id` = 1) group by `t3`.`t3_id` order by `link_alias_142`.`_field_166`,`t3`.`_field_139`,`link_alias_133`.`_field_72`,`t3`.`_field_135`,`link_alias_148`.`_field_156`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(`t3`.`t3_id` = 1)", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "multiple equal(1, `t3`.`t3_id`)" }, { "transformation": "constant_propagation", "resulting_condition": "multiple equal(1, `t3`.`t3_id`)" }, { "transformation": "trivial_condition_removal", "resulting_condition": "multiple equal(1, `t3`.`t3_id`)" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t3`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t4`", "row_may_be_null": true, "map_bit": 1, "depends_on_map_bits": [ 0 ] /* depends_on_map_bits */ }, { "table": "`t7` `link_alias_142`", "row_may_be_null": true, "map_bit": 2, "depends_on_map_bits": [ 0, 1 ] /* depends_on_map_bits */ }, { "table": "`t6`", "row_may_be_null": true, "map_bit": 3, "depends_on_map_bits": [ 0, 1, 2 ] /* depends_on_map_bits */ }, { "table": "`t1` `link_alias_133`", "row_may_be_null": true, "map_bit": 4, "depends_on_map_bits": [ 0, 1, 2, 3 ] /* depends_on_map_bits */ }, { "table": "`t2`", "row_may_be_null": true, "map_bit": 5, "depends_on_map_bits": [ 0, 1, 2, 3, 4 ] /* depends_on_map_bits */ }, { "table": "`t5` `link_alias_148`", "row_may_be_null": true, "map_bit": 6, "depends_on_map_bits": [ 0, 1, 2, 3, 4, 5 ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ { "table": "`t3`", "field": "t3_id", "equals": "1", "null_rejecting": false }, { "table": "`t4`", "field": "seq_0_id", "equals": "1", "null_rejecting": false }, { "table": "`t7` `link_alias_142`", "field": "t7_id", "equals": "`t4`.`seq_1_id`", "null_rejecting": true }, { "table": "`t6`", "field": "seq_0_id", "equals": "1", "null_rejecting": false }, { "table": "`t1` `link_alias_133`", "field": "t1_id", "equals": "`t6`.`seq_1_id`", "null_rejecting": true }, { "table": "`t2`", "field": "seq_0_id", "equals": "1", "null_rejecting": false }, { "table": "`t5` `link_alias_148`", "field": "t5_id", "equals": "`t2`.`seq_1_id`", "null_rejecting": true } ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t3`", "rows": 1, "cost": 1, "table_type": "const", "empty": false }, { "table": "`t4`", "range_analysis": { "table_scan": { "rows": 2, "cost": 4.5083 } /* table_scan */, "potential_range_indexes": [ { "index": "PRIMARY", "usable": true, "key_parts": [ "seq_0_id", "seq_1_id" ] /* key_parts */ } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "PRIMARY", "cost": 1.4435, "chosen": true } /* best_covering_index_scan */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */, "analyzing_range_alternatives": { "range_scan_alternatives": [ { "index": "PRIMARY", "ranges": [ "1 <= seq_0_id <= 1" ] /* ranges */, "index_dives_for_eq_ranges": true, "rowid_ordered": false, "using_mrr": false, "index_only": true, "rows": 1, "cost": 1.21, "chosen": true } ] /* range_scan_alternatives */, "analyzing_roworder_intersect": { "usable": false, "cause": "too_few_roworder_scans" } /* analyzing_roworder_intersect */ } /* analyzing_range_alternatives */, "chosen_range_access_summary": { "range_access_plan": { "type": "range_scan", "index": "PRIMARY", "rows": 1, "ranges": [ "1 <= seq_0_id <= 1" ] /* ranges */ } /* range_access_plan */, "rows_for_plan": 1, "cost_for_plan": 1.21, "chosen": true } /* chosen_range_access_summary */ } /* range_analysis */ }, { "table": "`t7` `link_alias_142`", "table_scan": { "rows": 3, "cost": 2 } /* table_scan */ }, { "table": "`t6`", "range_analysis": { "table_scan": { "rows": 3, "cost": 4.7125 } /* table_scan */, "potential_range_indexes": [ { "index": "PRIMARY", "usable": true, "key_parts": [ "seq_0_id", "seq_1_id" ] /* key_parts */ } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "PRIMARY", "cost": 1.687, "chosen": true } /* best_covering_index_scan */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */, "analyzing_range_alternatives": { "range_scan_alternatives": [ { "index": "PRIMARY", "ranges": [ "1 <= seq_0_id <= 1" ] /* ranges */, "index_dives_for_eq_ranges": true, "rowid_ordered": false, "using_mrr": false, "index_only": true, "rows": 1, "cost": 1.21, "chosen": true } ] /* range_scan_alternatives */, "analyzing_roworder_intersect": { "usable": false, "cause": "too_few_roworder_scans" } /* analyzing_roworder_intersect */ } /* analyzing_range_alternatives */, "chosen_range_access_summary": { "range_access_plan": { "type": "range_scan", "index": "PRIMARY", "rows": 1, "ranges": [ "1 <= seq_0_id <= 1" ] /* ranges */ } /* range_access_plan */, "rows_for_plan": 1, "cost_for_plan": 1.21, "chosen": true } /* chosen_range_access_summary */ } /* range_analysis */ }, { "table": "`t1` `link_alias_133`", "table_scan": { "rows": 3, "cost": 2 } /* table_scan */ }, { "table": "`t2`", "range_analysis": { "table_scan": { "rows": 3, "cost": 4.7125 } /* table_scan */, "potential_range_indexes": [ { "index": "PRIMARY", "usable": true, "key_parts": [ "seq_0_id", "seq_1_id" ] /* key_parts */ } ] /* potential_range_indexes */, "best_covering_index_scan": { "index": "PRIMARY", "cost": 1.687, "chosen": true } /* best_covering_index_scan */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */, "analyzing_range_alternatives": { "range_scan_alternatives": [ { "index": "PRIMARY", "ranges": [ "1 <= seq_0_id <= 1" ] /* ranges */, "index_dives_for_eq_ranges": true, "rowid_ordered": false, "using_mrr": false, "index_only": true, "rows": 1, "cost": 1.21, "chosen": true } ] /* range_scan_alternatives */, "analyzing_roworder_intersect": { "usable": false, "cause": "too_few_roworder_scans" } /* analyzing_roworder_intersect */ } /* analyzing_range_alternatives */, "chosen_range_access_summary": { "range_access_plan": { "type": "range_scan", "index": "PRIMARY", "rows": 1, "ranges": [ "1 <= seq_0_id <= 1" ] /* ranges */ } /* range_access_plan */, "rows_for_plan": 1, "cost_for_plan": 1.21, "chosen": true } /* chosen_range_access_summary */ } /* range_analysis */ }, { "table": "`t5` `link_alias_148`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ "`t3`" ] /* plan_prefix */, "table": "`t4`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "PRIMARY", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "range", "range_details": { "used_index": "PRIMARY" } /* range_details */, "chosen": false, "cause": "heuristic_index_cheaper" } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 1.2, "rest_of_plan": [ { "plan_prefix": [ "`t3`", "`t4`" ] /* plan_prefix */, "table": "`t7` `link_alias_142`", "best_access_path": { "considered_access_paths": [ { "access_type": "eq_ref", "index": "PRIMARY", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "scan", "cost": 2.6, "rows": 3, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 2.4, "rest_of_plan": [ { "plan_prefix": [ "`t3`", "`t4`", "`t7` `link_alias_142`" ] /* plan_prefix */, "table": "`t6`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "PRIMARY", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "range", "range_details": { "used_index": "PRIMARY" } /* range_details */, "chosen": false, "cause": "heuristic_index_cheaper" } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 3.6, "rest_of_plan": [ { "plan_prefix": [ "`t3`", "`t4`", "`t7` `link_alias_142`", "`t6`" ] /* plan_prefix */, "table": "`t1` `link_alias_133`", "best_access_path": { "considered_access_paths": [ { "access_type": "eq_ref", "index": "PRIMARY", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "scan", "cost": 2.6, "rows": 3, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 4.8, "rest_of_plan": [ { "plan_prefix": [ "`t3`", "`t4`", "`t7` `link_alias_142`", "`t6`", "`t1` `link_alias_133`" ] /* plan_prefix */, "table": "`t2`", "best_access_path": { "considered_access_paths": [ { "access_type": "ref", "index": "PRIMARY", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "range", "range_details": { "used_index": "PRIMARY" } /* range_details */, "chosen": false, "cause": "heuristic_index_cheaper" } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 6, "rest_of_plan": [ { "plan_prefix": [ "`t3`", "`t4`", "`t7` `link_alias_142`", "`t6`", "`t1` `link_alias_133`", "`t2`" ] /* plan_prefix */, "table": "`t5` `link_alias_148`", "best_access_path": { "considered_access_paths": [ { "access_type": "eq_ref", "index": "PRIMARY", "rows": 1, "cost": 1.2, "chosen": true }, { "access_type": "scan", "cost": 2.4, "rows": 2, "chosen": false, "cause": "cost" } ] /* considered_access_paths */ } /* best_access_path */, "added_to_eq_ref_extension": true, "condition_filtering_pct": 100, "rows_for_plan": 1, "cost_for_plan": 7.2, "chosen": true } ] /* rest_of_plan */ } ] /* rest_of_plan */ } ] /* rest_of_plan */ } ] /* rest_of_plan */ } ] /* rest_of_plan */ } ] /* considered_execution_plans */ }, { "condition_on_constant_tables": "1", "condition_value": true }, { "attaching_conditions_to_tables": { "original_condition": "1", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t4`", "attached": null }, { "table": "`t7` `link_alias_142`", "attached": null }, { "table": "`t6`", "attached": null }, { "table": "`t1` `link_alias_133`", "attached": null }, { "table": "`t2`", "attached": null }, { "table": "`t5` `link_alias_148`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "clause_processing": { "clause": "ORDER BY", "original_clause": "`link_alias_142`.`_field_166`,'1999-02-25 22:43:32',`link_alias_133`.`_field_72`,'0000-00-00 00:00:00',`link_alias_148`.`_field_156`", "items": [ { "item": "`link_alias_142`.`_field_166`" }, { "item": "'1999-02-25 22:43:32'", "uses_only_constant_tables": true }, { "item": "`link_alias_133`.`_field_72`" }, { "item": "'0000-00-00 00:00:00'", "uses_only_constant_tables": true }, { "item": "`link_alias_148`.`_field_156`" } ] /* items */, "resulting_clause_is_simple": false, "resulting_clause": "`link_alias_142`.`_field_166`,`link_alias_133`.`_field_72`,`link_alias_148`.`_field_156`" } /* clause_processing */ }, { "clause_processing": { "clause": "GROUP BY", "original_clause": "'1'", "items": [ { "item": "'1'", "uses_only_constant_tables": true } ] /* items */, "resulting_clause_is_simple": true, "resulting_clause": "" } /* clause_processing */ }, { "refine_plan": [ { "table": "`t4`" }, { "table": "`t7` `link_alias_142`" }, { "table": "`t6`" }, { "table": "`t1` `link_alias_133`" }, { "table": "`t2`" }, { "table": "`t5` `link_alias_148`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 drop table t1,t2,t3,t4,t5,t6,t7; # # Tracing of ORDER BY & GROUP BY simplification. # CREATE TABLE t1 ( pk INT, col_int_key INT, col_varchar_key VARCHAR(1), col_varchar_nokey VARCHAR(1) ); INSERT INTO t1 VALUES (10,7,'v','v'),(11,0,'s','s'),(12,9,'l','l'),(13,3,'y','y'),(14,4,'c','c'), (15,2,'i','i'),(16,5,'h','h'),(17,3,'q','q'),(18,1,'a','a'),(19,3,'v','v'), (20,6,'u','u'),(21,7,'s','s'),(22,5,'y','y'),(23,1,'z','z'),(24,204,'h','h'), (25,224,'p','p'),(26,9,'e','e'),(27,5,'i','i'),(28,0,'y','y'),(29,3,'w','w'); CREATE TABLE t2 ( pk INT, col_int_key INT, col_varchar_key VARCHAR(1), col_varchar_nokey VARCHAR(1), PRIMARY KEY (pk) ); INSERT INTO t2 VALUES (1,4,'b','b'),(2,8,'y','y'),(3,0,'p','p'),(4,0,'f','f'),(5,0,'p','p'), (6,7,'d','d'),(7,7,'f','f'),(8,5,'j','j'),(9,3,'e','e'),(10,188,'u','u'), (11,4,'v','v'),(12,9,'u','u'),(13,6,'i','i'),(14,1,'x','x'),(15,5,'l','l'), (16,6,'q','q'),(17,2,'n','n'),(18,4,'r','r'),(19,231,'c','c'),(20,4,'h','h'), (21,3,'k','k'),(22,3,'t','t'),(23,7,'t','t'),(24,6,'k','k'),(25,7,'g','g'), (26,9,'z','z'),(27,4,'n','n'),(28,4,'j','j'),(29,2,'l','l'),(30,1,'d','d'), (31,2,'t','t'),(32,194,'y','y'),(33,2,'i','i'),(34,3,'j','j'),(35,8,'r','r'), (36,4,'b','b'),(37,9,'o','o'),(38,4,'k','k'),(39,5,'a','a'),(40,5,'f','f'), (41,9,'t','t'),(42,3,'c','c'),(43,8,'c','c'),(44,0,'r','r'),(45,98,'k','k'), (46,3,'l','l'),(47,1,'o','o'),(48,0,'t','t'),(49,189,'v','v'),(50,8,'x','x'), (51,3,'j','j'),(52,3,'x','x'),(53,9,'k','k'),(54,6,'o','o'),(55,8,'z','z'), (56,3,'n','n'),(57,9,'c','c'),(58,5,'d','d'),(59,9,'s','s'),(60,2,'j','j'), (61,2,'w','w'),(62,5,'f','f'),(63,8,'p','p'),(64,6,'o','o'),(65,9,'f','f'), (66,0,'x','x'),(67,3,'q','q'),(68,6,'g','g'),(69,5,'x','x'),(70,8,'p','p'), (71,2,'q','q'),(72,120,'q','q'),(73,25,'v','v'),(74,1,'g','g'),(75,3,'l','l'), (76,1,'w','w'),(77,3,'h','h'),(78,153,'c','c'),(79,5,'o','o'),(80,9,'o','o'), (81,1,'v','v'),(82,8,'y','y'),(83,7,'d','d'),(84,6,'p','p'),(85,2,'z','z'), (86,4,'t','t'),(87,7,'b','b'),(88,3,'y','y'),(89,8,'k','k'),(90,4,'c','c'), (91,6,'z','z'),(92,1,'t','t'),(93,7,'o','o'),(94,1,'u','u'),(95,0,'t','t'), (96,2,'k','k'),(97,7,'u','u'),(98,2,'b','b'),(99,1,'m','m'),(100,5,'o','o'); SELECT SUM(alias2.col_varchar_nokey) , alias2.pk AS field2 FROM t1 AS alias1 STRAIGHT_JOIN t2 AS alias2 ON alias2.pk = alias1.col_int_key WHERE alias1.pk GROUP BY field2 ORDER BY alias1.col_int_key,alias2.pk ; SUM(alias2.col_varchar_nokey) field2 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 9 Warnings: Warning 1292 Truncated incorrect DOUBLE value: 'f' Warning 1292 Truncated incorrect DOUBLE value: 'e' Warning 1292 Truncated incorrect DOUBLE value: 'p' Warning 1292 Truncated incorrect DOUBLE value: 'f' Warning 1292 Truncated incorrect DOUBLE value: 'y' Warning 1292 Truncated incorrect DOUBLE value: 'p' Warning 1292 Truncated incorrect DOUBLE value: 'p' Warning 1292 Truncated incorrect DOUBLE value: 'b' Warning 1292 Truncated incorrect DOUBLE value: 'p' Warning 1292 Truncated incorrect DOUBLE value: 'd' Warning 1292 Truncated incorrect DOUBLE value: 'f' Warning 1292 Truncated incorrect DOUBLE value: 'p' Warning 1292 Truncated incorrect DOUBLE value: 'b' Warning 1292 Truncated incorrect DOUBLE value: 'e' Warning 1292 Truncated incorrect DOUBLE value: 'p' Warning 1292 Truncated incorrect DOUBLE value: 'p' SELECT * FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES SELECT SUM(alias2.col_varchar_nokey) , alias2.pk AS field2 FROM t1 AS alias1 STRAIGHT_JOIN t2 AS alias2 ON alias2.pk = alias1.col_int_key WHERE alias1.pk GROUP BY field2 ORDER BY alias1.col_int_key,alias2.pk { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select sum(`alias2`.`col_varchar_nokey`) AS `SUM(alias2.col_varchar_nokey)`,`alias2`.`pk` AS `field2` from `t1` `alias1` straight_join `t2` `alias2` where (`alias1`.`pk` and (`alias2`.`pk` = `alias1`.`col_int_key`)) group by `field2` order by `alias1`.`col_int_key`,`alias2`.`pk`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(`alias1`.`pk` and (`alias2`.`pk` = `alias1`.`col_int_key`))", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(`alias1`.`pk` and multiple equal(`alias2`.`pk`, `alias1`.`col_int_key`))" }, { "transformation": "constant_propagation", "resulting_condition": "(`alias1`.`pk` and multiple equal(`alias2`.`pk`, `alias1`.`col_int_key`))" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(`alias1`.`pk` and multiple equal(`alias2`.`pk`, `alias1`.`col_int_key`))" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1` `alias1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t2` `alias2`", "row_may_be_null": false, "map_bit": 1, "depends_on_map_bits": [ 0 ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ { "table": "`t2` `alias2`", "field": "pk", "equals": "`alias1`.`col_int_key`", "null_rejecting": true } ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1` `alias1`", "table_scan": { "rows": 20, "cost": 2 } /* table_scan */ }, { "table": "`t2` `alias2`", "const_keys_added": { "keys": [ "PRIMARY" ] /* keys */, "cause": "group_by" } /* const_keys_added */, "range_analysis": { "table_scan": { "rows": 100, "cost": 24.588 } /* table_scan */, "potential_range_indexes": [ { "index": "PRIMARY", "usable": true, "key_parts": [ "pk" ] /* key_parts */ } ] /* potential_range_indexes */, "setup_range_conditions": [ ] /* setup_range_conditions */, "group_index_range": { "chosen": false, "cause": "not_single_table" } /* group_index_range */ } /* range_analysis */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1` `alias1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 20, "access_type": "scan", "resulting_rows": 18, "cost": 6.0977, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 18, "cost_for_plan": 6.0977, "rest_of_plan": [ { "plan_prefix": [ "`t1` `alias1`" ] /* plan_prefix */, "table": "`t2` `alias2`", "best_access_path": { "considered_access_paths": [ { "access_type": "eq_ref", "index": "PRIMARY", "rows": 1, "cost": 21.6, "chosen": true }, { "rows_to_scan": 100, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 100, "cost": 362.49, "chosen": false } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 18, "cost_for_plan": 27.698, "chosen": true } ] /* rest_of_plan */ } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": "((`alias2`.`pk` = `alias1`.`col_int_key`) and `alias1`.`pk`)", "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`t1` `alias1`", "attached": "(`alias1`.`pk` and (`alias1`.`col_int_key` is not null))" }, { "table": "`t2` `alias2`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "clause_processing": { "clause": "ORDER BY", "original_clause": "`alias1`.`col_int_key`,`alias2`.`pk`", "items": [ { "item": "`alias1`.`col_int_key`" }, { "item": "`alias2`.`pk`", "eq_ref_to_preceding_items": true } ] /* items */, "resulting_clause_is_simple": true, "resulting_clause": "`alias1`.`col_int_key`" } /* clause_processing */ }, { "clause_processing": { "clause": "GROUP BY", "original_clause": "`field2`", "items": [ { "item": "`alias2`.`pk`" } ] /* items */, "resulting_clause_is_simple": false, "resulting_clause": "`field2`" } /* clause_processing */ }, { "refine_plan": [ { "table": "`t1` `alias1`" }, { "table": "`t2` `alias2`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ { "creating_tmp_table": { "tmp_table_info": { "table": "intermediate_tmp_table", "row_length": 18, "key_length": 4, "unique_constraint": false, "location": "memory (heap)", "row_limit_estimate": 58254 } /* tmp_table_info */ } /* creating_tmp_table */ }, { "filesort_information": [ { "direction": "asc", "table": "intermediate_tmp_table", "field": "col_int_key" } ] /* filesort_information */, "filesort_priority_queue_optimization": { "usable": false, "cause": "not applicable (no LIMIT)" } /* filesort_priority_queue_optimization */, "filesort_execution": [ ] /* filesort_execution */, "filesort_summary": { "rows": 8, "examined_rows": 8, "number_of_tmp_files": 0, "sort_buffer_size": "NNN", "sort_mode": "" } /* filesort_summary */ } ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 DROP TABLE t1,t2; # # Trace of "condition on constant tables" # create table t1(a int) engine=myisam; insert into t1 values(26); create table t2(b int primary key, c int) engine=myisam; insert into t2 values(1,100),(2,200),(3,300); select * from t1,t2 where t1.a+t2.c=cos(10) and t2.b=2; a b c SELECT * FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select * from t1,t2 where t1.a+t2.c=cos(10) and t2.b=2 { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `t1`.`a` AS `a`,`t2`.`b` AS `b`,`t2`.`c` AS `c` from `t1` join `t2` where (((`t1`.`a` + `t2`.`c`) = cos(10)) and (`t2`.`b` = 2))" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "condition_processing": { "condition": "WHERE", "original_condition": "(((`t1`.`a` + `t2`.`c`) = cos(10)) and (`t2`.`b` = 2))", "steps": [ { "transformation": "equality_propagation", "resulting_condition": "(((`t1`.`a` + `t2`.`c`) = cos(10)) and multiple equal(2, `t2`.`b`))" }, { "transformation": "constant_propagation", "resulting_condition": "(((`t1`.`a` + `t2`.`c`) = cos(10)) and multiple equal(2, `t2`.`b`))" }, { "transformation": "trivial_condition_removal", "resulting_condition": "(((`t1`.`a` + `t2`.`c`) = cos(10)) and multiple equal(2, `t2`.`b`))" } ] /* steps */ } /* condition_processing */ }, { "substitute_generated_columns": { } /* substitute_generated_columns */ }, { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`t2`", "row_may_be_null": false, "map_bit": 1, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "ref_optimizer_key_uses": [ { "table": "`t2`", "field": "b", "equals": "2", "null_rejecting": false } ] /* ref_optimizer_key_uses */ }, { "rows_estimation": [ { "table": "`t1`", "rows": 1, "cost": 1, "table_type": "system", "empty": false }, { "table": "`t2`", "rows": 1, "cost": 1, "table_type": "const", "empty": false } ] /* rows_estimation */ }, { "condition_on_constant_tables": "(('26' + '200') = cos(10))", "condition_value": false } ] /* steps */, "empty_result": { "cause": "Impossible WHERE noticed after reading const tables" } /* empty_result */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 drop table t1,t2; # # Trace of non-default db # create table t1(a int); insert into t1 values(1),(2),(3); create database mysqltest2; create table mysqltest2.t2(a int); insert into mysqltest2.t2 values(1),(2); select * from t1,mysqltest2.t2; a a 1 1 1 2 2 1 2 2 3 1 3 2 SELECT * FROM INFORMATION_SCHEMA.OPTIMIZER_TRACE; QUERY TRACE MISSING_BYTES_BEYOND_MAX_MEM_SIZE INSUFFICIENT_PRIVILEGES select * from t1,mysqltest2.t2 { "steps": [ { "join_preparation": { "select#": 1, "steps": [ { "expanded_query": "/* select#1 */ select `t1`.`a` AS `a`,`mysqltest2`.`t2`.`a` AS `a` from `t1` join `mysqltest2`.`t2`" } ] /* steps */ } /* join_preparation */ }, { "join_optimization": { "select#": 1, "steps": [ { "table_dependencies": [ { "table": "`t1`", "row_may_be_null": false, "map_bit": 0, "depends_on_map_bits": [ ] /* depends_on_map_bits */ }, { "table": "`mysqltest2`.`t2`", "row_may_be_null": false, "map_bit": 1, "depends_on_map_bits": [ ] /* depends_on_map_bits */ } ] /* table_dependencies */ }, { "rows_estimation": [ { "table": "`t1`", "table_scan": { "rows": 3, "cost": 2 } /* table_scan */ }, { "table": "`mysqltest2`.`t2`", "table_scan": { "rows": 2, "cost": 2 } /* table_scan */ } ] /* rows_estimation */ }, { "considered_execution_plans": [ { "plan_prefix": [ ] /* plan_prefix */, "table": "`mysqltest2`.`t2`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 2, "access_type": "scan", "resulting_rows": 2, "cost": 2.4034, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 2, "cost_for_plan": 2.4034, "rest_of_plan": [ { "plan_prefix": [ "`mysqltest2`.`t2`" ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 3, "access_type": "scan", "using_join_cache": true, "buffers_needed": 1, "resulting_rows": 3, "cost": 3.2052, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 6, "cost_for_plan": 5.6086, "chosen": true } ] /* rest_of_plan */ }, { "plan_prefix": [ ] /* plan_prefix */, "table": "`t1`", "best_access_path": { "considered_access_paths": [ { "rows_to_scan": 3, "access_type": "scan", "resulting_rows": 3, "cost": 2.6051, "chosen": true } ] /* considered_access_paths */ } /* best_access_path */, "condition_filtering_pct": 100, "rows_for_plan": 3, "cost_for_plan": 2.6051, "pruned_by_heuristic": true } ] /* considered_execution_plans */ }, { "attaching_conditions_to_tables": { "original_condition": null, "attached_conditions_computation": [ ] /* attached_conditions_computation */, "attached_conditions_summary": [ { "table": "`mysqltest2`.`t2`", "attached": null }, { "table": "`t1`", "attached": null } ] /* attached_conditions_summary */ } /* attaching_conditions_to_tables */ }, { "refine_plan": [ { "table": "`mysqltest2`.`t2`" }, { "table": "`t1`" } ] /* refine_plan */ } ] /* steps */ } /* join_optimization */ }, { "join_execution": { "select#": 1, "steps": [ ] /* steps */ } /* join_execution */ } ] /* steps */ } 0 0 drop table t1; drop database mysqltest2;