Skip to content

M
MariaDB
Commit bd43f39b authored by Sergei Petrunia's avatar Sergei Petrunia
Browse files
Options

MDEV-24325: Optimizer trace doesn't cover LATERAL DERIVED 

Provide basic coverage in the Optimizer Trace
parent e1a514d5
Hide whitespace changes
Inline Side-by-side
Showing with 183 additions and 1 deletion
mysql-test/main/opt_trace.result
View file @ bd43f39b
......@@ -9070,4 +9070,120 @@ json_detailed(json_extract(trace, '$**.condition_processing'))
}
]
drop table t1,t2,t3;
#
# MDEV-24325: Optimizer trace doesn't cover LATERAL DERIVED
#
create table t1 (a int, b int, index idx_b(b)) engine=myisam;
insert into t1 values
(8,3), (5,7), (1,2), (2,1), (9,7), (7,5), (2,2), (7,3),
(9,3), (8,1), (4,5), (2,3);
create table t2 (a int, b int, c char(127), index idx_a(a)) engine=myisam;
insert into t2 values
(7,10,'x'), (1,20,'a'), (2,23,'b'), (7,18,'z'), (1,30,'c'),
(4,71,'d'), (3,15,'x'), (7,82,'y'), (8,12,'t'), (4,15,'b'),
(11,33,'a'), (10,42,'u'), (4,53,'p'), (10,17,'r'), (2,90,'x'),
(17,10,'s'), (11,20,'v'), (12,23,'y'), (17,18,'a'), (11,30,'d'),
(24,71,'h'), (23,15,'i'), (27,82,'k'), (28,12,'p'), (24,15,'q'),
(31,33,'f'), (30,42,'h'), (40,53,'m'), (30,17,'o'), (21,90,'b'),
(37,10,'e'), (31,20,'g'), (32,23,'f'), (37,18,'n'), (41,30,'l'),
(54,71,'j'), (53,15,'w'), (57,82,'z'), (58,12,'k'), (54,15,'p'),
(61,33,'c'), (60,42,'a'), (62,53,'x'), (67,17,'g'), (64,90,'v');
insert into t2 select a+10, b+10, concat(c,'f') from t2;
analyze table t1,t2;
Table Op Msg_type Msg_text
test.t1 analyze status Engine-independent statistics collected
test.t1 analyze status OK
test.t2 analyze status Engine-independent statistics collected
test.t2 analyze status OK
explain
select t1.a,t.s,t.m
from t1 join
(select a, sum(t2.b) as s, min(t2.c) as m from t2 group by t2.a) t
on t1.a=t.a
where t1.b < 3;
id select_type table type possible_keys key key_len ref rows Extra
1 PRIMARY t1 range idx_b idx_b 5 NULL 4 Using index condition; Using where
1 PRIMARY <derived2> ref key0 key0 5 test.t1.a 2
2 LATERAL DERIVED t2 ref idx_a idx_a 5 test.t1.a 1
select
json_detailed(json_extract(trace, '$**.choose_best_splitting'))
from
information_schema.optimizer_trace;
json_detailed(json_extract(trace, '$**.choose_best_splitting'))
[
[
{
"considered_execution_plans":
[
{
"plan_prefix":
[
],
"table": "t2",
"best_access_path":
{
"considered_access_paths":
[
{
"access_type": "ref",
"index": "idx_a",
"used_range_estimates": false,
"cause": "not available",
"rows": 1.8367,
"cost": 2.000585794,
"chosen": true
},
{
"type": "scan",
"chosen": false,
"cause": "cost"
}
],
"chosen_access_method":
{
"type": "ref",
"records": 1.8367,
"cost": 2.000585794,
"uses_join_buffering": false
}
},
"rows_for_plan": 1.8367,
"cost_for_plan": 2.367925794,
"cost_for_sorting": 1.8367,
"estimated_join_cardinality": 1.8367
}
]
},
{
"best_splitting":
{
"table": "t2",
"key": "idx_a",
"record_count": 4,
"cost": 2.488945919,
"unsplit_cost": 25.72361682
}
}
]
]
select
json_detailed(json_extract(trace, '$**.lateral_derived'))
from
information_schema.optimizer_trace;
json_detailed(json_extract(trace, '$**.lateral_derived'))
[
{
"startup_cost": 9.955783677,
"splitting_cost": 2.488945919,
"records": 1
}
]
drop table t1,t2;
set optimizer_trace='enabled=off';
mysql-test/main/opt_trace.test
View file @ bd43f39b
......@@ -788,4 +788,53 @@ from
drop table t1,t2,t3;
--echo #
--echo # MDEV-24325: Optimizer trace doesn't cover LATERAL DERIVED
--echo #
create table t1 (a int, b int, index idx_b(b)) engine=myisam;
insert into t1 values
(8,3), (5,7), (1,2), (2,1), (9,7), (7,5), (2,2), (7,3),
(9,3), (8,1), (4,5), (2,3);
create table t2 (a int, b int, c char(127), index idx_a(a)) engine=myisam;
insert into t2 values
(7,10,'x'), (1,20,'a'), (2,23,'b'), (7,18,'z'), (1,30,'c'),
(4,71,'d'), (3,15,'x'), (7,82,'y'), (8,12,'t'), (4,15,'b'),
(11,33,'a'), (10,42,'u'), (4,53,'p'), (10,17,'r'), (2,90,'x'),
(17,10,'s'), (11,20,'v'), (12,23,'y'), (17,18,'a'), (11,30,'d'),
(24,71,'h'), (23,15,'i'), (27,82,'k'), (28,12,'p'), (24,15,'q'),
(31,33,'f'), (30,42,'h'), (40,53,'m'), (30,17,'o'), (21,90,'b'),
(37,10,'e'), (31,20,'g'), (32,23,'f'), (37,18,'n'), (41,30,'l'),
(54,71,'j'), (53,15,'w'), (57,82,'z'), (58,12,'k'), (54,15,'p'),
(61,33,'c'), (60,42,'a'), (62,53,'x'), (67,17,'g'), (64,90,'v');
insert into t2 select a+10, b+10, concat(c,'f') from t2;
analyze table t1,t2;
explain
select t1.a,t.s,t.m
from t1 join
(select a, sum(t2.b) as s, min(t2.c) as m from t2 group by t2.a) t
on t1.a=t.a
where t1.b < 3;
#
# Just show that choose_best_splitting function has coverage in the
# optimizer trace and re-optmization of child select inside it is distinct
# from the rest of join optimization.
select
json_detailed(json_extract(trace, '$**.choose_best_splitting'))
from
information_schema.optimizer_trace;
# Same as above. just to show that splitting plan has some coverage in the
# trace.
select
json_detailed(json_extract(trace, '$**.lateral_derived'))
from
information_schema.optimizer_trace;
drop table t1,t2;
set optimizer_trace='enabled=off';
sql/opt_split.cc
View file @ bd43f39b
......@@ -187,6 +187,7 @@
#include "mariadb.h"
#include "sql_select.h"
#include "opt_trace.h"
/* Info on a splitting field */
struct SplM_field_info
......@@ -957,6 +958,7 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count,
The key for splitting was chosen, look for the plan for this key
in the cache
*/
Json_writer_array spl_trace(thd, "choose_best_splitting");
spl_plan= spl_opt_info->find_plan(best_table, best_key, best_key_parts);
if (!spl_plan &&
(spl_plan= (SplM_plan_info *) thd->alloc(sizeof(SplM_plan_info))) &&
......@@ -988,6 +990,16 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count,
spl_plan->cost= join->best_positions[join->table_count-1].read_time +
+ oper_cost;
if (unlikely(thd->trace_started()))
{
Json_writer_object wrapper(thd);
Json_writer_object find_trace(thd, "best_splitting");
find_trace.add("table", best_table->alias.c_ptr());
find_trace.add("key", best_table->key_info[best_key].name);
find_trace.add("record_count", record_count);
find_trace.add("cost", spl_plan->cost);
find_trace.add("unsplit_cost", spl_opt_info->unsplit_cost);
}
memcpy((char *) spl_plan->best_positions,
(char *) join->best_positions,
sizeof(POSITION) * join->table_count);
......@@ -1014,6 +1026,11 @@ SplM_plan_info * JOIN_TAB::choose_best_splitting(double record_count,
{
startup_cost= record_count * spl_plan->cost;
records= (ha_rows) (records * spl_plan->split_sel);
Json_writer_object trace(thd, "lateral_derived");
trace.add("startup_cost", startup_cost);
trace.add("splitting_cost", spl_plan->cost);
trace.add("records", records);
}
else
startup_cost= spl_opt_info->unsplit_cost;
......
sql/sql_select.cc
View file @ bd43f39b
......@@ -7441,7 +7441,6 @@ best_access_path(JOIN *join,
DBUG_ENTER("best_access_path");
Json_writer_object trace_wrapper(thd, "best_access_path");
Json_writer_array trace_paths(thd, "considered_access_paths");
bitmap_clear_all(eq_join_set);
......@@ -7449,6 +7448,7 @@ best_access_path(JOIN *join,
if (s->table->is_splittable())
spl_plan= s->choose_best_splitting(record_count, remaining_tables);
Json_writer_array trace_paths(thd, "considered_access_paths");
if (s->keyuse)
{ /* Use key if possible */
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7