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MDEV-6995: EXPLAIN JSON and ORDER BY, GROUP BY, etc

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- Make ANALYZE correctly remember and report filesort() calls
- Temp.table use is collected but only basic info is reported.
This commit is contained in:
Sergei Petrunia
2015-06-06 00:32:27 +03:00
parent f7002c05ae
commit 93fc04ff1d
6 changed files with 339 additions and 46 deletions
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45
mysql-test/r/analyze_stmt_orderby.result
View File

@ -203,6 +203,10 @@ ANALYZE
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"filesort": {
"r_loops": 1,
"r_limit": 4,
"r_used_priority_queue": true,
"r_output_rows": 4,
"temporary_table": {
"table": {
"table_name": "t0",
@ -318,4 +322,45 @@ ANALYZE
}
}
drop table t2;
create table t2 (
a int,
b int,
c int
);
insert into t2
select
a.a+10*b.a+100*c.a,
b.a+10*c.a,
c.a
from t0 a, t0 b, t0 c;
analyze format=json
select MAX(b) from t2 where mod(a,2)=0 group by c;
ANALYZE
{
"query_block": {
"select_id": 1,
"r_loops": 1,
"r_total_time_ms": "REPLACED",
"filesort": {
"r_loops": 1,
"r_used_priority_queue": false,
"r_output_rows": 10,
"r_buffer_size": "REPLACED",
"temporary_table": {
"table": {
"table_name": "t2",
"access_type": "ALL",
"r_loops": 1,
"rows": 1000,
"r_rows": 1000,
"r_total_time_ms": "REPLACED",
"filtered": 100,
"r_filtered": 50,
"attached_condition": "((t2.a % 2) = 0)"
}
}
}
}
}
drop table t2;
drop table t0, t1;

20
mysql-test/t/analyze_stmt_orderby.test
View File

@ -69,5 +69,25 @@ select * from t0,t2 where t2.a=t0.a order by t0.a limit 4;
analyze format=json
select * from t0,t2 where t2.a=t0.a order by t0.a limit 4;
drop table t2;
create table t2 (
a int,
b int,
c int
);
insert into t2
select
a.a+10*b.a+100*c.a,
b.a+10*c.a,
c.a
from t0 a, t0 b, t0 c;
--replace_regex /"r_total_time_ms": [0-9]*[.]?[0-9]*/"r_total_time_ms": "REPLACED"/ /"r_buffer_size": "[^"]+"/"r_buffer_size": "REPLACED"/
analyze format=json
select MAX(b) from t2 where mod(a,2)=0 group by c;
drop table t2;
drop table t0, t1;

55
sql/sql_analyze_stmt.cc
View File

@ -23,7 +23,7 @@
#include "sql_select.h"
#include "my_json_writer.h"
void Filesort_tracker::print_json(Json_writer *writer)
void Filesort_tracker::print_json_members(Json_writer *writer)
{
const char *varied_str= "(varied across executions)";
writer->add_member("r_loops").add_ll(r_loops);
@ -60,3 +60,56 @@ void Filesort_tracker::print_json(Json_writer *writer)
}
}
/*
Report that we are doing a filesort.
@return
Tracker object to be used with filesort
*/
Filesort_tracker *Sort_and_group_tracker::report_sorting()
{
DBUG_ASSERT(cur_action < MAX_QEP_ACTIONS);
if (total_actions)
{
/* This is not the first execution. Check */
if (qep_actions[cur_action] != EXPL_ACTION_FILESORT)
{
varied_executions= true;
cur_action++;
if (!dummy_fsort_tracker)
dummy_fsort_tracker= new (current_thd->mem_root) Filesort_tracker();
return dummy_fsort_tracker;
}
return qep_actions_data[cur_action++].filesort_tracker;
}
Filesort_tracker *fs_tracker= new(current_thd->mem_root)Filesort_tracker();
qep_actions_data[cur_action].filesort_tracker= fs_tracker;
qep_actions[cur_action++]= EXPL_ACTION_FILESORT;
return fs_tracker;
}
void Sort_and_group_tracker::report_tmp_table(TABLE *tbl)
{
DBUG_ASSERT(cur_action < MAX_QEP_ACTIONS);
if (total_actions)
{
/* This is not the first execution. Check if the steps match. */
// todo: should also check that tmp.table kinds are the same.
if (qep_actions[cur_action] != EXPL_ACTION_TEMPTABLE)
varied_executions= true;
}
if (!varied_executions)
{
qep_actions[cur_action]= EXPL_ACTION_TEMPTABLE;
// qep_actions_data[cur_action]= ....
}
cur_action++;
}

155
sql/sql_analyze_stmt.h
View File

@ -214,7 +214,7 @@ public:
}
/* Functions to get the statistics */
void print_json(Json_writer *writer);
void print_json_members(Json_writer *writer);
ulonglong get_r_loops() { return r_loops; }
double get_avg_examined_rows()
@ -283,6 +283,7 @@ typedef enum
typedef enum
{
EXPL_ACTION_EOF, /* not-an-action */
EXPL_ACTION_FILESORT,
EXPL_ACTION_TEMPTABLE,
EXPL_ACTION_REMOVE_DUPS,
@ -329,12 +330,121 @@ typedef enum
///TODO: handle repeated execution with subselects!
*/
class Sort_and_group_tracker : public Sql_alloc
{
enum { MAX_QEP_ACTIONS = 5 };
/* Query actions in the order they were made. */
enum_qep_action qep_actions[MAX_QEP_ACTIONS];
/* Number for the next action */
int cur_action;
/*
Non-zero means there was already an execution which had
#total_actions actions
*/
int total_actions;
int get_n_actions()
{
return total_actions? total_actions: cur_action;
}
/*
TRUE<=>there were executions which took different sort/buffer/de-duplicate
routes. The counter values are not meaningful.
*/
bool varied_executions;
/* Details about query actions */
union
{
Filesort_tracker *filesort_tracker;
enum_tmp_table_use tmp_table;
}
qep_actions_data[MAX_QEP_ACTIONS];
Filesort_tracker *dummy_fsort_tracker;
public:
Sort_and_group_tracker() :
cur_action(0), total_actions(0), varied_executions(false),
dummy_fsort_tracker(NULL)
{}
/*************** Reporting interface ***************/
/* Report that join execution is started */
void report_join_start()
{
if (!total_actions && cur_action != 0)
{
/* This is a second execution */
total_actions= cur_action;
}
cur_action= 0;
}
/*
Report that a temporary table is created. The next step is to write to the
this tmp. table
*/
void report_tmp_table(TABLE *tbl);
/*
Report that we are doing a filesort.
@return
Tracker object to be used with filesort
*/
Filesort_tracker *report_sorting();
friend class Iterator;
/*************** Statistics retrieval interface ***************/
bool had_varied_executions() { return varied_executions; }
class Iterator
{
Sort_and_group_tracker *owner;
int idx;
public:
Iterator(Sort_and_group_tracker *owner_arg) :
owner(owner_arg), idx(owner_arg->get_n_actions() - 1)
{}
enum_qep_action get_next(Filesort_tracker **tracker/*,
enum_tmp_table_use *tmp_table_use*/)
{
/* Walk back through the array... */
if (idx < 0)
return EXPL_ACTION_EOF;
switch (owner->qep_actions[idx])
{
case EXPL_ACTION_FILESORT:
*tracker= owner->qep_actions_data[idx].filesort_tracker;
break;
case EXPL_ACTION_TEMPTABLE:
//*tmp_table_use= tmp_table_kind[tmp_table_idx++];
break;
default:
break;
}
return owner->qep_actions[idx--];
}
bool is_last_element() { return idx == -1; }
};
};
#if 0
class Sort_and_group_tracker : public Sql_alloc
{
enum { MAX_QEP_ACTIONS = 5 };
/* Query actions in the order they were made */
enum_qep_action qep_actions[MAX_QEP_ACTIONS];
/* Index in filesort_tracker or tmp_table_kind arrays */
int qep_action_idx[MAX_QEP_ACTIONS];
uint n_actions;
/*
@ -348,7 +458,7 @@ class Sort_and_group_tracker : public Sql_alloc
enum_tmp_table_use tmp_table_kind[2];
int cur_tmp_table;
friend class Explain_select;
//friend class Explain_select;
public:
Sort_and_group_tracker() :
@ -366,7 +476,10 @@ public:
cur_tmp_table= 0;
}
/* Report that a temporary table is created. */
/*
Report that a temporary table is created. The next step is to write to the
this tmp. table
*/
void report_tmp_table(TABLE *tbl)
{
DBUG_ASSERT(n_actions < MAX_QEP_ACTIONS);
@ -386,7 +499,43 @@ public:
return &filesort_tracker[cur_tracker++];
}
friend class Iterator;
/*************** Statistics retrieval interface ***************/
// need to iterate over steps
#if 0
class Iterator
{
Sort_and_group_tracker *owner;
uint idx;
int fs_tracker_idx;
//int tmp_table_idx;
public:
Iterator(Sort_and_group_tracker *owner_arg) :
owner(owner_arg), idx(0), fs_tracker_idx(0)//, tmp_table_idx(0)
{}
enum_qep_action get_next(Filesort_tracker **tracker/*,
enum_tmp_table_use *tmp_table_use*/)
{
/* Walk back through the array... */
if (idx >= owner->n_actions)
return EXPL_ACTION_EOF;
switch (owner->qep_actions[idx])
{
case EXPL_ACTION_FILESORT:
*tracker= &owner->filesort_tracker[fs_tracker_idx++];
break;
case EXPL_ACTION_TEMPTABLE:
//*tmp_table_use= tmp_table_kind[tmp_table_idx++];
break;
default:
break;
}
return owner->qep_actions[idx++];
}
};
#endif
//enum_tmp_table_use get_tmp_table_type() { return join_result_tmp_table; }
};
#endif

57
sql/sql_explain.cc
View File

@ -770,25 +770,37 @@ void Explain_select::print_explain_json(Explain_query *query,
}
Filesort_tracker *first_table_sort= NULL;
bool first_table_sort_used= false;
int started_objects= 0;
if (is_analyze)
{
/* ANALYZE has collected this part of query plan independently */
for (int i= ops_tracker.n_actions-1; i >= 0; i--)
if (ops_tracker.had_varied_executions())
{
if (ops_tracker.qep_actions[i] == EXPL_ACTION_FILESORT)
writer->add_member("varied-sort-and-tmp").start_object();
started_objects++;
}
else
{
if (i == 0)
Sort_and_group_tracker::Iterator iter(&ops_tracker);
enum_qep_action action;
Filesort_tracker *fs_tracker;
while ((action= iter.get_next(&fs_tracker)) != EXPL_ACTION_EOF)
{
/* filesort operation was the first in the pipeline */
first_table_sort= &ops_tracker.filesort_tracker[0];
if (action == EXPL_ACTION_FILESORT)
{
if (iter.is_last_element())
{
first_table_sort= fs_tracker;
break;
}
writer->add_member("filesort").start_object();
started_objects++;
fs_tracker->print_json_members(writer);
}
else if (ops_tracker.qep_actions[i] == EXPL_ACTION_TEMPTABLE)
else if (action == EXPL_ACTION_TEMPTABLE)
{
writer->add_member("temporary_table").start_object();
started_objects++;
@ -802,7 +814,7 @@ void Explain_select::print_explain_json(Explain_query *query,
writer->add_member("function").add_str(func);
*/
}
else if (ops_tracker.qep_actions[i] == EXPL_ACTION_REMOVE_DUPS)
else if (action == EXPL_ACTION_REMOVE_DUPS)
{
writer->add_member("duplicate_removal").start_object();
started_objects++;
@ -810,7 +822,10 @@ void Explain_select::print_explain_json(Explain_query *query,
else
DBUG_ASSERT(0);
}
}
if (first_table_sort)
first_table_sort_used= true;
}
else
{
@ -828,13 +843,15 @@ void Explain_select::print_explain_json(Explain_query *query,
}
else
{
fprintf(stderr, "Weird!\n");
if (using_filesort)
first_table_sort= &ops_tracker.filesort_tracker[0];
first_table_sort_used= true;
}
}
Explain_basic_join::print_explain_json_interns(query, writer, is_analyze,
first_table_sort);
first_table_sort,
first_table_sort_used);
for (;started_objects; started_objects--)
writer->end_object();
@ -852,7 +869,7 @@ void Explain_basic_join::print_explain_json(Explain_query *query,
writer->add_member("query_block").start_object();
writer->add_member("select_id").add_ll(select_id);
print_explain_json_interns(query, writer, is_analyze, NULL);
print_explain_json_interns(query, writer, is_analyze, NULL, false);
writer->end_object();
}
@ -862,7 +879,8 @@ void Explain_basic_join::
print_explain_json_interns(Explain_query *query,
Json_writer *writer,
bool is_analyze,
Filesort_tracker *first_table_sort)
Filesort_tracker *first_table_sort,
bool first_table_sort_used)
{
Json_writer_nesting_guard guard(writer);
for (uint i=0; i< n_join_tabs; i++)
@ -871,7 +889,11 @@ print_explain_json_interns(Explain_query *query,
writer->add_member("duplicates_removal").start_object();
join_tabs[i]->print_explain_json(query, writer, is_analyze,
(i==0)? first_table_sort : NULL);
first_table_sort,
first_table_sort_used);
first_table_sort= NULL;
first_table_sort_used= false;
if (join_tabs[i]->end_dups_weedout)
writer->end_object();
@ -1314,11 +1336,12 @@ void add_json_keyset(Json_writer *writer, const char *elem_name,
void Explain_table_access::print_explain_json(Explain_query *query,
Json_writer *writer,
bool is_analyze,
Filesort_tracker *fs_tracker)
Filesort_tracker *fs_tracker,
bool first_table_sort_used)
{
Json_writer_nesting_guard guard(writer);
if (fs_tracker)
if (first_table_sort_used)
{
/* filesort was invoked on this join tab before doing the join with the rest */
writer->add_member("read_sorted_file").start_object();
@ -1346,7 +1369,7 @@ void Explain_table_access::print_explain_json(Explain_query *query,
}
writer->add_member("filesort").start_object();
if (is_analyze)
fs_tracker->print_json(writer);
fs_tracker->print_json_members(writer);
}
if (bka_type.is_using_jbuf())
@ -1537,7 +1560,7 @@ void Explain_table_access::print_explain_json(Explain_query *query,
writer->end_object();
}
if (fs_tracker)
if (first_table_sort_used)
{
writer->end_object(); // filesort
writer->end_object(); // read_sorted_file
@ -1976,7 +1999,7 @@ void Explain_update::print_explain_json(Explain_query *query,
{
writer->add_member("filesort").start_object();
if (is_analyze)
filesort_tracker->print_json(writer);
filesort_tracker->print_json_members(writer);
doing_buffering= true;
}

7
sql/sql_explain.h
View File

@ -171,7 +171,8 @@ public:
void print_explain_json_interns(Explain_query *query, Json_writer *writer,
bool is_analyze,
Filesort_tracker *first_table_sort);
Filesort_tracker *first_table_sort,
bool first_table_sort_used);
/* A flat array of Explain structs for tables. */
Explain_table_access** join_tabs;
@ -704,7 +705,9 @@ public:
uint select_id, const char *select_type,
bool using_temporary, bool using_filesort);
void print_explain_json(Explain_query *query, Json_writer *writer,
bool is_analyze, Filesort_tracker *fs_tracker);
bool is_analyze,
Filesort_tracker *fs_tracker,
bool first_table_sort_used);
private:
void append_tag_name(String *str, enum explain_extra_tag tag);