GIF89a;
Mini Shell
Mini Shell
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 */
},
{
"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 */
},
{
"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`
select locate("\"view\": \"v1\"", TRACE) != 0
from information_schema.OPTIMIZER_TRACE;
locate("\"view\": \"v1\"", TRACE) != 0
1
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 */
},
{
"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_indices": [
{
"index": "a",
"usable": true,
"key_parts": [
"a"
] /* key_parts */
}
] /* potential_range_indices */,
"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": 3.41,
"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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4034,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4034,
"rows_for_plan": 2,
"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`",
"access_type": "index_scan"
}
] /* 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": [
{
"transformations_to_nested_joins": {
"transformations": [
"parenthesis_removal"
] /* transformations */,
"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`)"
} /* transformations_to_nested_joins */
},
{
"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 */
},
{
"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": [
{
"access_type": "scan",
"rows": 4,
"cost": 2.8068,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.8068,
"rows_for_plan": 4,
"rest_of_plan": [
{
"plan_prefix": [
"`t1`"
] /* plan_prefix */,
"table": "`t2`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 4,
"cost": 5.207,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 8.0138,
"rows_for_plan": 16,
"rest_of_plan": [
{
"plan_prefix": [
"`t1`",
"`t2`"
] /* plan_prefix */,
"table": "`t3`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 4,
"cost": 14.808,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 22.822,
"rows_for_plan": 64,
"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": "<if>(is_not_null_compl(t2..t3), (`t2`.`i` = `t1`.`i`), true)"
},
{
"table": "`t3`",
"attached": "(<if>(found_match(t3), <if>(found_match(t2..t3), isnull(`t3`.`i`), true), true) and <if>(is_not_null_compl(t3), (`t3`.`i` = `t1`.`i`), true))"
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"refine_plan": [
{
"table": "`t1`",
"access_type": "table_scan"
},
{
"table": "`t2`",
"access_type": "table_scan"
},
{
"table": "`t3`",
"access_type": "table_scan"
}
] /* 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');
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`"
},
{
"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_having_conditions": [
] /* evaluating_constant_having_conditions */
} /* transformation */
}
] /* steps */
} /* join_preparation */
},
{
"expanded_query": "/* select#1 */ select `t1`.`f2` AS `f2` from (`t1` straight_join (`t2` join `t3` on((`t3`.`f2` = `t2`.`f2`))) on((`t3`.`f2` = `t2`.`f2`))) having (not(<in_optimizer>(('v','i'),<exists>(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((<cache>('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(min(`t1`.`f2`))))))) order by `t1`.`f2`"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"transformations_to_nested_joins": {
"transformations": [
"JOIN_condition_to_WHERE",
"parenthesis_removal"
] /* transformations */,
"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(<in_optimizer>(('v','i'),<exists>(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((<cache>('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(min(`t1`.`f2`))))))) order by `t1`.`f2`"
} /* transformations_to_nested_joins */
},
{
"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(<in_optimizer>(('v','i'),<exists>(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((<cache>('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(min(`t1`.`f2`)))))))",
"steps": [
{
"transformation": "constant_propagation",
"subselect_evaluation": [
] /* subselect_evaluation */,
"resulting_condition": "(not(<in_optimizer>(('v','i'),<exists>(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((<cache>('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(min(`t1`.`f2`)))))))"
},
{
"transformation": "trivial_condition_removal",
"subselect_evaluation": [
] /* subselect_evaluation */,
"resulting_condition": "(not(<in_optimizer>(('v','i'),<exists>(/* select#2 */ select `t1`.`f2`,min(`t1`.`f2`) from `t1` having (((<cache>('v') = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>('i') = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(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": "`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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4098,
"chosen": true,
"use_tmp_table": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4098,
"rows_for_plan": 2,
"rest_of_plan": [
{
"plan_prefix": [
"`t1`"
] /* plan_prefix */,
"table": "`t3`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 1,
"cost": 2.4049,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 4.8147,
"rows_for_plan": 2,
"rest_of_plan": [
{
"plan_prefix": [
"`t1`",
"`t3`"
] /* plan_prefix */,
"table": "`t2`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 2,
"cost": 2.8099,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 7.6246,
"rows_for_plan": 4,
"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": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 2,
"cost": 2.8098,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 5.2196,
"rows_for_plan": 4,
"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`",
"access_type": "table_scan"
},
{
"table": "`t3`",
"access_type": "table_scan"
},
{
"table": "`t2`",
"access_type": "table_scan"
}
] /* 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_optimization": {
"select#": 2,
"steps": [
{
"condition_processing": {
"condition": "HAVING",
"original_condition": "(((<cache>(<cache>('v')) = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>(<cache>('i')) = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(min(`t1`.`f2`)))",
"steps": [
{
"transformation": "constant_propagation",
"resulting_condition": "(((<cache>(<cache>('v')) = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>(<cache>('i')) = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(min(`t1`.`f2`)))"
},
{
"transformation": "trivial_condition_removal",
"resulting_condition": "(((<cache>(<cache>('v')) = `t1`.`f2`) or isnull(`t1`.`f2`)) and ((<cache>(<cache>('i')) = min(`t1`.`f2`)) or isnull(min(`t1`.`f2`))) and <is_not_null_test>(`t1`.`f2`) and <is_not_null_test>(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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4098,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4098,
"rows_for_plan": 2,
"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 */
},
{
"transformation": {
"select#": 2,
"from": "IN (SELECT)",
"to": "EXISTS (CORRELATED SELECT)",
"put_1_in_SELECT_list": true
} /* 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`",
"access_type": "table_scan"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 2,
"steps": [
] /* steps */
} /* join_execution */
}
] /* steps */
} /* subselect_execution */
},
{
"subselect_execution": {
"select#": 2,
"steps": [
{
"join_execution": {
"select#": 2,
"steps": [
] /* steps */
} /* join_execution */
}
] /* steps */
} /* subselect_execution */
},
{
"subselect_execution": {
"select#": 2,
"steps": [
{
"join_execution": {
"select#": 2,
"steps": [
] /* steps */
} /* join_execution */
}
] /* steps */
} /* subselect_execution */
},
{
"subselect_execution": {
"select#": 2,
"steps": [
{
"join_execution": {
"select#": 2,
"steps": [
] /* steps */
} /* join_execution */
}
] /* steps */
} /* subselect_execution */
}
] /* filesort_execution */,
"filesort_summary": {
"rows": 4,
"examined_rows": 4,
"number_of_tmp_files": 0,
"sort_buffer_size": "NNN",
"sort_mode": "<sort_key, rowid>"
} /* 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#": 2,
"steps": [
{
"expanded_query": "/* select#2 */ select sum(`t1`.`a`) AS `x` from `t1` group by `t1`.`b`"
}
] /* steps */
} /* join_preparation */
},
{
"join_preparation": {
"select#": 1,
"steps": [
{
"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": [
{
"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": [
{
"access_type": "scan",
"rows": 3,
"cost": 2.6066,
"chosen": true,
"use_tmp_table": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.6066,
"rows_for_plan": 3,
"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`",
"access_type": "table_scan"
}
] /* 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": [
{
"access_type": "scan",
"rows": 3,
"cost": 10.75,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 10.75,
"rows_for_plan": 3,
"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`",
"access_type": "table_scan"
}
] /* 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": "<sort_key, rowid>"
} /* 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#": 3,
"steps": [
{
"expanded_query": "/* select#3 */ select 2"
}
] /* steps */
} /* join_preparation */
},
{
"subselect_execution": {
"select#": 3,
"steps": [
{
"join_optimization": {
"select#": 3,
"steps": [
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 3,
"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#": 4,
"steps": [
{
"expanded_query": "/* select#4 */ select count(0) from `t1`"
}
] /* steps */
} /* join_preparation */
},
{
"subselect_execution": {
"select#": 4,
"steps": [
{
"join_optimization": {
"select#": 4,
"steps": [
] /* steps */,
"empty_result": {
"cause": "Select tables optimized away"
} /* empty_result */
} /* join_optimization */
},
{
"join_execution": {
"select#": 4,
"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#": 5,
"steps": [
{
"expanded_query": "/* select#5 */ select count(`t1`.`a`) from `t1` where (`t1`.`a` > 0)"
}
] /* steps */
} /* join_preparation */
},
{
"subselect_execution": {
"select#": 5,
"steps": [
{
"join_optimization": {
"select#": 5,
"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 */
},
{
"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": [
{
"access_type": "scan",
"rows": 3,
"cost": 2.6051,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.6051,
"rows_for_plan": 3,
"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`",
"access_type": "table_scan"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 5,
"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#": 6,
"steps": [
{
"expanded_query": "/* select#6 */ select count(`t1`.`a`) from `t1` where (`t1`.`a` > 1)"
}
] /* steps */
} /* join_preparation */
},
{
"subselect_execution": {
"select#": 6,
"steps": [
{
"join_optimization": {
"select#": 6,
"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 */
},
{
"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": [
{
"access_type": "scan",
"rows": 3,
"cost": 2.6051,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.6051,
"rows_for_plan": 3,
"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`",
"access_type": "table_scan"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 6,
"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#": 2,
"steps": [
{
"expanded_query": "/* select#2 */ select 42"
}
] /* steps */
} /* join_preparation */
}
] /* 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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4034,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4034,
"rows_for_plan": 2,
"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`",
"access_type": "table_scan"
}
] /* 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#": 3,
"steps": [
{
"expanded_query": "/* select#3 */ select (2 + x@0)"
}
] /* steps */
} /* join_preparation */
},
{
"subselect_execution": {
"select#": 3,
"steps": [
{
"join_optimization": {
"select#": 3,
"steps": [
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 3,
"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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4098,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4098,
"rows_for_plan": 2,
"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`",
"access_type": "table_scan"
}
] /* 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": [
{
"transformations_to_nested_joins": {
"transformations": [
"parenthesis_removal"
] /* transformations */,
"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`))"
} /* transformations_to_nested_joins */
},
{
"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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4107,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4107,
"rows_for_plan": 2,
"rest_of_plan": [
{
"plan_prefix": [
"`t1` `table2`",
"`t3` `table1`"
] /* plan_prefix */,
"table": "`t2` `table3`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 1,
"cost": 2.405,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 4.8157,
"rows_for_plan": 2,
"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_indices": [
{
"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_indices */,
"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_indices": [
{
"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_indices */,
"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": "<if>(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`",
"access_type": "table_scan"
},
{
"table": "`t2` `table3`",
"access_type": "index_scan"
}
] /* 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 type possible_keys key key_len ref rows Extra
1 PRIMARY t0 ALL NULL NULL NULL NULL 10 Using where
2 DEPENDENT SUBQUERY t1 index a a 5 NULL 10 Using where; Using index
2 DEPENDENT SUBQUERY t2 ref a a 5 test.t1.a 1 Using index
2 DEPENDENT SUBQUERY t3 ref a a 5 test.t1.a 1 Using index
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 <in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"condition_processing": {
"condition": "WHERE",
"original_condition": "<in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))",
"steps": [
{
"transformation": "equality_propagation",
"subselect_evaluation": [
] /* subselect_evaluation */,
"resulting_condition": "<in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))"
},
{
"transformation": "constant_propagation",
"subselect_evaluation": [
] /* subselect_evaluation */,
"resulting_condition": "<in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))"
},
{
"transformation": "trivial_condition_removal",
"subselect_evaluation": [
] /* subselect_evaluation */,
"resulting_condition": "<in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))"
}
] /* steps */
} /* condition_processing */
},
{
"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": [
{
"access_type": "scan",
"rows": 10,
"cost": 4.0171,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 4.0171,
"rows_for_plan": 10,
"chosen": true
}
] /* considered_execution_plans */
},
{
"attaching_conditions_to_tables": {
"original_condition": "<in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))",
"attached_conditions_computation": [
] /* attached_conditions_computation */,
"attached_conditions_summary": [
{
"table": "`t0`",
"attached": "<in_optimizer>(`t0`.`a`,<exists>(/* 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 (<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`))))"
}
] /* attached_conditions_summary */
} /* attaching_conditions_to_tables */
},
{
"refine_plan": [
{
"table": "`t0`",
"access_type": "table_scan"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_explain": {
"select#": 1,
"steps": [
{
"join_optimization": {
"select#": 2,
"steps": [
{
"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 ((<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))"
} /* transformations_to_nested_joins */
},
{
"condition_processing": {
"condition": "WHERE",
"original_condition": "((<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and (`t2`.`a` = `t1`.`a`) and (`t3`.`a` = `t1`.`a`))",
"steps": [
{
"transformation": "equality_propagation",
"resulting_condition": "((<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and multiple equal(`t2`.`a`, `t1`.`a`, `t3`.`a`))"
},
{
"transformation": "constant_propagation",
"resulting_condition": "((<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and multiple equal(`t2`.`a`, `t1`.`a`, `t3`.`a`))"
},
{
"transformation": "trivial_condition_removal",
"resulting_condition": "((<cache>(`t0`.`a`) = (`t2`.`a` + `t3`.`a`)) and multiple equal(`t2`.`a`, `t1`.`a`, `t3`.`a`))"
}
] /* steps */
} /* condition_processing */
},
{
"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
},
{
"access_type": "scan",
"rows": 10,
"cost": 4.022,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 4.022,
"rows_for_plan": 10,
"rest_of_plan": [
{
"plan_prefix": [
"`t1`"
] /* plan_prefix */,
"table": "`t2`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "ref",
"index": "a",
"rows": 1,
"cost": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.422,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 16.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.423,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 28.022,
"rows_for_plan": 10,
"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
},
{
"access_type": "scan",
"rows": 10,
"cost": 4.022,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 4.022,
"rows_for_plan": 10,
"rest_of_plan": [
{
"plan_prefix": [
"`t2`"
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "ref",
"index": "a",
"rows": 1,
"cost": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.422,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 16.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.423,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 28.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.423,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 28.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.422,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 16.022,
"rows_for_plan": 10,
"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
},
{
"access_type": "scan",
"rows": 10,
"cost": 4.022,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 4.022,
"rows_for_plan": 10,
"rest_of_plan": [
{
"plan_prefix": [
"`t3`"
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "ref",
"index": "a",
"rows": 1,
"cost": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.422,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 16.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.423,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 28.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.423,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 28.022,
"rows_for_plan": 10,
"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": 10.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 8,
"cost": 18.422,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 16.022,
"rows_for_plan": 10,
"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 (<cache>(`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_indices": [
{
"index": "a",
"usable": true,
"key_parts": [
"a"
] /* key_parts */
}
] /* potential_range_indices */,
"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": "(<cache>(`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`",
"access_type": "index_scan"
},
{
"table": "`t2`"
},
{
"table": "`t3`"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"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#": 2,
"steps": [
{
"expanded_query": "/* select#2 */ 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"
}
] /* steps */
} /* join_preparation */
},
{
"join_preparation": {
"select#": 1,
"steps": [
{
"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` on((`t1`.`OBJECTID` = `t2`.`ID`))) join `t3` on((`t1`.`OBJECTID` = `t3`.`ID`))) group by `t2`.`PARID` order by `DATA` desc) `tmp`"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"join_optimization": {
"select#": 2,
"steps": [
{
"transformations_to_nested_joins": {
"transformations": [
"JOIN_condition_to_WHERE",
"parenthesis_removal"
] /* transformations */,
"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"
} /* transformations_to_nested_joins */
},
{
"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 */
},
{
"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_indices": [
{
"index": "t2_ID_IDX",
"usable": false,
"cause": "not_applicable"
},
{
"index": "t2_PARID_IDX",
"usable": true,
"key_parts": [
"PARID"
] /* key_parts */
}
] /* potential_range_indices */,
"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": 0.8,
"cost": 0.96,
"chosen": true
},
{
"access_type": "scan",
"cost": 3.6,
"rows": 8,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 0.96,
"rows_for_plan": 0.8,
"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,
"chosen": true
},
{
"access_type": "scan",
"cost": 3.8,
"rows": 9,
"cause": "cost",
"chosen": false
}
] /* 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,
"chosen": true
},
{
"access_type": "scan",
"cost": 3.8,
"rows": 9,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.88,
"rows_for_plan": 1.6,
"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": 0.9,
"cost": 1.08,
"chosen": true
},
{
"access_type": "scan",
"cost": 3.8,
"rows": 9,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 1.08,
"rows_for_plan": 0.9,
"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": [
{
"access_type": "scan",
"rows": 2,
"cost": 10.5,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 10.5,
"rows_for_plan": 2,
"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`",
"access_type": "table_scan"
}
] /* 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);
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);
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": [
{
"transformations_to_nested_joins": {
"transformations": [
"parenthesis_removal"
] /* transformations */,
"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`"
} /* transformations_to_nested_joins */
},
{
"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 */
},
{
"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_indices": [
{
"index": "PRIMARY",
"usable": true,
"key_parts": [
"seq_0_id",
"seq_1_id"
] /* key_parts */
}
] /* potential_range_indices */,
"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": 2.21,
"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 */
},
{
"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_indices": [
{
"index": "PRIMARY",
"usable": true,
"key_parts": [
"seq_0_id",
"seq_1_id"
] /* key_parts */
}
] /* potential_range_indices */,
"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": 2.21,
"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 */
},
{
"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_indices": [
{
"index": "PRIMARY",
"usable": true,
"key_parts": [
"seq_0_id",
"seq_1_id"
] /* key_parts */
}
] /* potential_range_indices */,
"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": 2.21,
"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 */
},
{
"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": "scan",
"cost": 2.4,
"rows": 2,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 1.2,
"rows_for_plan": 1,
"rest_of_plan": [
{
"plan_prefix": [
"`t3`",
"`t4`"
] /* plan_prefix */,
"table": "`t7` `link_alias_142`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "ref",
"index": "PRIMARY",
"rows": 1,
"cost": 1.2,
"chosen": true
},
{
"access_type": "scan",
"cost": 2.6,
"rows": 3,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 2.4,
"rows_for_plan": 1,
"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": "scan",
"cost": 2.6,
"rows": 3,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 3.6,
"rows_for_plan": 1,
"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": "ref",
"index": "PRIMARY",
"rows": 1,
"cost": 1.2,
"chosen": true
},
{
"access_type": "scan",
"cost": 2.6,
"rows": 3,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 4.8,
"rows_for_plan": 1,
"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": "scan",
"cost": 2.6,
"rows": 3,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 6,
"rows_for_plan": 1,
"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": "ref",
"index": "PRIMARY",
"rows": 1,
"cost": 1.2,
"chosen": true
},
{
"access_type": "scan",
"cost": 2.4,
"rows": 2,
"cause": "cost",
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"added_to_eq_ref_extension": true,
"cost_for_plan": 7.2,
"rows_for_plan": 1,
"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` on((`alias2`.`pk` = `alias1`.`col_int_key`))) where `alias1`.`pk` group by `field2` order by `alias1`.`col_int_key`,`alias2`.`pk`"
}
] /* steps */
} /* join_preparation */
},
{
"join_optimization": {
"select#": 1,
"steps": [
{
"transformations_to_nested_joins": {
"transformations": [
"JOIN_condition_to_WHERE",
"parenthesis_removal"
] /* transformations */,
"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`"
} /* transformations_to_nested_joins */
},
{
"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 */
},
{
"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_indices": [
{
"index": "PRIMARY",
"usable": true,
"key_parts": [
"pk"
] /* key_parts */
}
] /* potential_range_indices */,
"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": [
{
"access_type": "scan",
"rows": 20,
"cost": 6.0977,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 6.0977,
"rows_for_plan": 20,
"rest_of_plan": [
{
"plan_prefix": [
"`t1` `alias1`"
] /* plan_prefix */,
"table": "`t2` `alias2`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "ref",
"index": "PRIMARY",
"rows": 1,
"cost": 20.2,
"chosen": true
},
{
"access_type": "scan",
"using_join_cache": true,
"rows": 75,
"cost": 307.49,
"chosen": false
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 30.098,
"rows_for_plan": 20,
"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`",
"access_type": "table_scan"
},
{
"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": "<sort_key, rowid>"
} /* 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 */
},
{
"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": [
{
"access_type": "scan",
"rows": 2,
"cost": 2.4034,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.4034,
"rows_for_plan": 2,
"rest_of_plan": [
{
"plan_prefix": [
"`mysqltest2`.`t2`"
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"using_join_cache": true,
"rows": 3,
"cost": 3.2052,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 5.6086,
"rows_for_plan": 6,
"chosen": true
}
] /* rest_of_plan */
},
{
"plan_prefix": [
] /* plan_prefix */,
"table": "`t1`",
"best_access_path": {
"considered_access_paths": [
{
"access_type": "scan",
"rows": 3,
"cost": 2.6051,
"chosen": true
}
] /* considered_access_paths */
} /* best_access_path */,
"cost_for_plan": 2.6051,
"rows_for_plan": 3,
"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`",
"access_type": "table_scan"
},
{
"table": "`t1`",
"access_type": "table_scan"
}
] /* refine_plan */
}
] /* steps */
} /* join_optimization */
},
{
"join_execution": {
"select#": 1,
"steps": [
] /* steps */
} /* join_execution */
}
] /* steps */
} 0 0
drop table t1;
drop database mysqltest2;
./BlackJoker Mini Shell 1.0