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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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101
sql/sql_explain.cc
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@ -770,47 +770,62 @@ 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
{
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)
{
if (i == 0)
if (action == EXPL_ACTION_FILESORT)
{
/* filesort operation was the first in the pipeline */
first_table_sort= &ops_tracker.filesort_tracker[0];
break;
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 (action == EXPL_ACTION_TEMPTABLE)
{
writer->add_member("temporary_table").start_object();
started_objects++;
/*
if (tmp == EXPL_TMP_TABLE_BUFFER)
func= "buffer";
else if (tmp == EXPL_TMP_TABLE_GROUP)
func= "group-by";
else
func= "distinct";
writer->add_member("function").add_str(func);
*/
}
else if (action == EXPL_ACTION_REMOVE_DUPS)
{
writer->add_member("duplicate_removal").start_object();
started_objects++;
}
writer->add_member("filesort").start_object();
started_objects++;
}
else if (ops_tracker.qep_actions[i] == EXPL_ACTION_TEMPTABLE)
{
writer->add_member("temporary_table").start_object();
started_objects++;
/*
if (tmp == EXPL_TMP_TABLE_BUFFER)
func= "buffer";
else if (tmp == EXPL_TMP_TABLE_GROUP)
func= "group-by";
else
func= "distinct";
writer->add_member("function").add_str(func);
*/
DBUG_ASSERT(0);
}
else if (ops_tracker.qep_actions[i] == EXPL_ACTION_REMOVE_DUPS)
{
writer->add_member("duplicate_removal").start_object();
started_objects++;
}
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;
}