database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-29 05:21:33 +03:00
Code Activity

MDEV-34041 Display additional information for materialized subqueries in EXPLAIN/ANALYZE FORMAT=JSON

Browse Source 
This commits adds the "materialization" block to the output of
EXPLAIN/ANALYZE FORMAT=JSON when materialized subqueries are involved
into processing. In the case of ANALYZE additional runtime information
is displayed, such as:
  - chosen strategy of materialization
  - number of partial match/index lookup loops
  - sizes of partial match buffers
This commit is contained in:
Oleg Smirnov
2024-05-04 19:50:55 +07:00
parent a5e4c34991
commit aae3233c4f
14 changed files with 2024 additions and 615 deletions
Download Patch File Download Diff File Expand all files Collapse all files

55
sql/sql_explain.cc
View File

@ -24,6 +24,7 @@
#include "my_json_writer.h"
#include "opt_range.h"
#include "sql_expression_cache.h"
#include "item_subselect.h"
const char * STR_DELETING_ALL_ROWS= "Deleting all rows";
const char * STR_IMPOSSIBLE_WHERE= "Impossible WHERE";
@ -782,6 +783,18 @@ bool Explain_node::print_explain_json_cache(Json_writer *writer,
}
bool Explain_node::print_explain_json_subq_materialization(Json_writer *writer,
bool is_analyze)
{
if (subq_materialization)
{
subq_materialization->print_explain_json(writer, is_analyze);
return true;
}
return false;
}
Explain_basic_join::~Explain_basic_join()
{
if (join_tabs)
@ -929,6 +942,8 @@ void Explain_select::print_explain_json(Explain_query *query,
Json_writer_nesting_guard guard(writer);
bool started_cache= print_explain_json_cache(writer, is_analyze);
bool started_subq_mat= print_explain_json_subq_materialization(writer,
is_analyze);
if (message ||
select_type == pushed_derived_text ||
@ -1032,6 +1047,8 @@ void Explain_select::print_explain_json(Explain_query *query,
writer->end_object();
}
if (started_subq_mat)
writer->end_object();
if (started_cache)
writer->end_object();
}
@ -2693,3 +2710,41 @@ void Explain_range_checked_fer::print_json(Json_writer *writer,
writer->end_object();
}
}
void Explain_subq_materialization::print_explain_json(Json_writer *writer,
bool is_analyze)
{
writer->add_member("materialization").start_object();
if (is_analyze)
tracker.print_json_members(writer);
}
void Subq_materialization_tracker::print_json_members(Json_writer *writer) const
{
writer->add_member("r_strategy").add_str(get_exec_strategy());
if (loops_count)
writer->add_member("r_loops").add_ull(loops_count);
if (index_lookups_count)
writer->add_member("r_index_lookups").add_ull(index_lookups_count);
if (partial_matches_count)
writer->add_member("r_partial_matches").add_ull(partial_matches_count);
if (partial_match_buffer_size)
{
writer->add_member("r_partial_match_buffer_size").
add_size(partial_match_buffer_size);
}
if (partial_match_array_sizes.elements())
{
writer->add_member("r_partial_match_array_sizes").start_array();
for(size_t i= 0; i < partial_match_array_sizes.elements(); i++)
writer->add_ull(partial_match_array_sizes[i]);
writer->end_array();
}
}