diff options
Diffstat (limited to 'sql/sql_explain.cc')
| -rw-r--r-- | sql/sql_explain.cc | 250 |
1 files changed, 210 insertions, 40 deletions
diff --git a/sql/sql_explain.cc b/sql/sql_explain.cc index 7c3918bfd20..d767592bd99 100644 --- a/sql/sql_explain.cc +++ b/sql/sql_explain.cc @@ -541,7 +541,8 @@ uint Explain_union::make_union_table_name(char *buf) int Explain_union::print_explain(Explain_query *query, select_result_sink *output, uint8 explain_flags, - bool is_analyze) + bool is_analyze, + bool is_eliminated) { THD *thd= output->thd; MEM_ROOT *mem_root= thd->mem_root; @@ -642,7 +643,8 @@ int Explain_union::print_explain(Explain_query *query, void Explain_union::print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze, - bool no_tmp_tbl) + bool no_tmp_tbl, + bool is_eliminated) { Json_writer_nesting_guard guard(writer); char table_name_buffer[SAFE_NAME_LEN]; @@ -713,8 +715,9 @@ int Explain_node::print_explain_for_children(Explain_query *query, { for (int i= 0; i < (int) children.elements(); i++) { - Explain_node *node= query->get_node(children.at(i)); - if (node->print_explain(query, output, explain_flags, is_analyze)) + Explain_node *node= query->get_node(children.at(i).select_no); + if (node->print_explain(query, output, explain_flags, is_analyze, + children.at(i).is_eliminated)) return 1; } return 0; @@ -758,7 +761,7 @@ void Explain_node::print_explain_json_for_children(Explain_query *query, bool started= false; for (int i= 0; i < (int) children.elements(); i++) { - Explain_node *node= query->get_node(children.at(i)); + Explain_node *node= query->get_node(children.at(i).select_no); /* Derived tables are printed inside Explain_table_access objects */ if (!is_connection_printable_in_json(node->connection_type)) @@ -771,7 +774,8 @@ void Explain_node::print_explain_json_for_children(Explain_query *query, } writer->start_object(); - node->print_explain_json(query, writer, is_analyze, no_tmp_tbl); + node->print_explain_json(query, writer, is_analyze, no_tmp_tbl, + children.at(i).is_eliminated); writer->end_object(); } @@ -821,7 +825,8 @@ Explain_basic_join::~Explain_basic_join() int Explain_select::print_explain(Explain_query *query, select_result_sink *output, - uint8 explain_flags, bool is_analyze) + uint8 explain_flags, bool is_analyze, + bool is_eliminated) { THD *thd= output->thd; MEM_ROOT *mem_root= thd->mem_root; @@ -885,13 +890,20 @@ int Explain_select::print_explain(Explain_query *query, } } - for (uint i=0; i< n_join_tabs; i++) + /* + If there is no elimination of the whole node then do the first pass: + print the tables which are not eliminated individually + */ + if (!is_eliminated) { - join_tabs[i]->print_explain(output, explain_flags, is_analyze, select_id, - select_type, using_tmp, using_fs); - if (i == 0) + for (uint i= 0; i < n_join_tabs; i++) { - /* + if (unlikely(join_tabs[i]->is_eliminated)) + continue; + join_tabs[i]->print_explain(output, explain_flags, is_analyze, + select_id, select_type, using_tmp, + using_fs); + /* "Using temporary; Using filesort" should only be shown near the 1st table */ @@ -899,11 +911,25 @@ int Explain_select::print_explain(Explain_query *query, using_fs= false; } } + + /* + Second pass: print the tables which have been eliminated + either due to the whole node elimination or individually + */ + for (uint i= 0; i < n_join_tabs; i++) + { + if (unlikely(join_tabs[i]->is_eliminated || is_eliminated)) + join_tabs[i]->print_explain(output, explain_flags, is_analyze, + select_id, select_type, false, + false, is_eliminated); + } + for (uint i=0; i< n_join_tabs; i++) { Explain_basic_join* nest; if ((nest= join_tabs[i]->sjm_nest)) - nest->print_explain(query, output, explain_flags, is_analyze); + nest->print_explain(query, output, explain_flags, is_analyze, + is_eliminated); } } @@ -913,7 +939,8 @@ int Explain_select::print_explain(Explain_query *query, int Explain_basic_join::print_explain(Explain_query *query, select_result_sink *output, - uint8 explain_flags, bool is_analyze) + uint8 explain_flags, bool is_analyze, + bool is_eliminated) { for (uint i=0; i< n_join_tabs; i++) { @@ -952,9 +979,20 @@ void Explain_select::add_linkage(Json_writer *writer) void Explain_select::print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze, - bool no_tmp_tbl) + bool no_tmp_tbl, + bool is_eliminated) { Json_writer_nesting_guard guard(writer); + if (unlikely(is_eliminated)) + { + writer->add_member("query_block").start_object(); + writer->add_member("select_id").add_ll(select_id); + writer->add_member("eliminated").add_bool(true); + Explain_basic_join::print_explain_json_interns(query, writer, is_analyze, + no_tmp_tbl, is_eliminated); + writer->end_object(); + return; + } bool started_cache= print_explain_json_cache(writer, is_analyze); @@ -1059,7 +1097,7 @@ void Explain_select::print_explain_json(Explain_query *query, } Explain_basic_join::print_explain_json_interns(query, writer, is_analyze, - no_tmp_tbl); + no_tmp_tbl, is_eliminated); for (;started_objects; started_objects--) writer->end_object(); @@ -1139,12 +1177,14 @@ void Explain_aggr_window_funcs::print_json_members(Json_writer *writer, void Explain_basic_join::print_explain_json(Explain_query *query, Json_writer *writer, - bool is_analyze, bool no_tmp_tbl) + bool is_analyze, bool no_tmp_tbl, + bool is_eliminated) { writer->add_member("query_block").start_object(); writer->add_member("select_id").add_ll(select_id); - print_explain_json_interns(query, writer, is_analyze, no_tmp_tbl); + print_explain_json_interns(query, writer, is_analyze, no_tmp_tbl, + is_eliminated); writer->end_object(); } @@ -1153,27 +1193,50 @@ void Explain_basic_join::print_explain_json(Explain_query *query, void Explain_basic_join:: print_explain_json_interns(Explain_query *query, Json_writer *writer, - bool is_analyze, bool no_tmp_tbl) + bool is_analyze, bool no_tmp_tbl, + bool is_eliminated) { { Json_writer_array loop(writer, "nested_loop"); - for (uint i=0; i< n_join_tabs; i++) + + /* + If there is no elimination of the whole node then do the first pass: + print the tables which are not eliminated individually + */ + if (!is_eliminated) { - if (join_tabs[i]->start_dups_weedout) + for (uint i= 0; i < n_join_tabs; i++) { - writer->start_object(); - writer->add_member("duplicates_removal"); - writer->start_array(); - } + if (unlikely(join_tabs[i]->is_eliminated)) + continue; + if (join_tabs[i]->start_dups_weedout) + { + writer->start_object(); + writer->add_member("duplicates_removal"); + writer->start_array(); + } - join_tabs[i]->print_explain_json(query, writer, is_analyze, no_tmp_tbl); + join_tabs[i]->print_explain_json(query, writer, is_analyze, + no_tmp_tbl); - if (join_tabs[i]->end_dups_weedout) - { - writer->end_array(); - writer->end_object(); + if (join_tabs[i]->end_dups_weedout) + { + writer->end_array(); + writer->end_object(); + } } } + + /* + Second pass: print the tables which have been eliminated + either due to the whole node elimination or individually + */ + for (uint i= 0; i < n_join_tabs; i++) + { + if (unlikely(join_tabs[i]->is_eliminated || is_eliminated)) + join_tabs[i]->print_explain_json(query, writer, is_analyze, + no_tmp_tbl, true); + } } // "nested_loop" print_explain_json_for_children(query, writer, is_analyze, no_tmp_tbl); } @@ -1332,8 +1395,14 @@ double Explain_table_access::get_r_filtered() int Explain_table_access::print_explain(select_result_sink *output, uint8 explain_flags, bool is_analyze, uint select_id, const char *select_type, - bool using_temporary, bool using_filesort) + bool using_temporary, bool using_filesort, + bool is_parent_node_eliminated) { + // Check whether the table is eliminated itself or its parent node + if (unlikely(is_eliminated || is_parent_node_eliminated)) + return print_explain_eliminated(output, explain_flags, is_analyze, + select_id, select_type); + THD *thd= output->thd; // note: for SHOW EXPLAIN, this is target thd. MEM_ROOT *mem_root= thd->mem_root; @@ -1552,6 +1621,72 @@ int Explain_table_access::print_explain(select_result_sink *output, uint8 explai } +int Explain_table_access::print_explain_eliminated(select_result_sink *output, + uint8 explain_flags, + bool is_analyze, + uint select_id, + const char *select_type) +{ + THD *thd= output->thd; // note: for SHOW EXPLAIN, this is target thd. + MEM_ROOT *mem_root= thd->mem_root; + + List<Item> item_list; + Item *item_null= new (mem_root) Item_null(thd); + + /* `id` column */ + item_list.push_back(new (mem_root) Item_int(thd, (int32) select_id), + mem_root); + + /* `select_type` column */ + push_str(thd, &item_list, select_type); + + /* `table` column */ + push_string(thd, &item_list, &table_name); + + /* `partitions` column */ + if (explain_flags & DESCRIBE_PARTITIONS) + item_list.push_back(item_null, mem_root); + + /* `type` column */ + push_str(thd, &item_list, "Eliminated"); + + /* `possible_keys` column */ + item_list.push_back(item_null, mem_root); + + /* `key` */ + item_list.push_back(item_null, mem_root); + + /* `key_len` */ + item_list.push_back(item_null, mem_root); + + /* `ref` */ + item_list.push_back(item_null, mem_root); + + /* `rows` */ + item_list.push_back(item_null, mem_root); + + /* `r_rows` */ + if (is_analyze) + item_list.push_back(item_null, mem_root); + + /* `filtered` */ + if (explain_flags &DESCRIBE_EXTENDED || is_analyze) + item_list.push_back(item_null, mem_root); + + /* `r_filtered` */ + if (is_analyze) + item_list.push_back(item_null, mem_root); + + /* `Extra` */ + push_str(thd, &item_list, ""); + + if (output->send_data(item_list)) + return 1; + + return 0; +} + + /** Adds copy of the string to the list @@ -1760,8 +1895,15 @@ void Explain_rowid_filter::print_explain_json(Explain_query *query, void Explain_table_access::print_explain_json(Explain_query *query, Json_writer *writer, - bool is_analyze, bool no_tmp_tbl) + bool is_analyze, bool no_tmp_tbl, + bool is_parent_node_eliminated) { + if (unlikely(is_eliminated || is_parent_node_eliminated)) + { + print_explain_json_eliminated(query, writer); + return; + } + Json_writer_object jsobj(writer); if (pre_join_sort) @@ -2005,6 +2147,30 @@ void Explain_table_access::print_explain_json(Explain_query *query, } +void Explain_table_access::print_explain_json_eliminated(Explain_query *query, + Json_writer *writer) +{ + Json_writer_object jsobj(writer); + writer->add_member("table").start_object(); + writer->add_member("table_name").add_str(table_name); + writer->add_member("access_type").add_str("Eliminated"); + if (derived_select_number) + { + /* This is a derived table. Print its contents here */ + writer->add_member("materialized").start_object(); + Explain_node *node= query->get_node(derived_select_number); + if (node->get_type() == Explain_node::EXPLAIN_SELECT && + ((Explain_select *) node)->is_lateral) + { + writer->add_member("lateral").add_ll(1); + } + node->print_explain_json(query, writer, false, false, true); + writer->end_object(); + } + writer->end_object(); +} + + /* Elements in this array match members of enum explain_extra_tag, defined in sql_explain.h @@ -2275,8 +2441,8 @@ void Explain_quick_select::print_key_len(String *str) int Explain_delete::print_explain(Explain_query *query, select_result_sink *output, - uint8 explain_flags, - bool is_analyze) + uint8 explain_flags, bool is_analyze, + bool is_eliminated) { if (deleting_all_rows) { @@ -2290,7 +2456,7 @@ int Explain_delete::print_explain(Explain_query *query, else { return Explain_update::print_explain(query, output, explain_flags, - is_analyze); + is_analyze, is_eliminated); } } @@ -2298,7 +2464,8 @@ int Explain_delete::print_explain(Explain_query *query, void Explain_delete::print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze, - bool no_tmp_tbl) + bool no_tmp_tbl, + bool is_eliminated) { Json_writer_nesting_guard guard(writer); @@ -2320,7 +2487,8 @@ void Explain_delete::print_explain_json(Explain_query *query, int Explain_update::print_explain(Explain_query *query, select_result_sink *output, uint8 explain_flags, - bool is_analyze) + bool is_analyze, + bool is_eliminated) { StringBuffer<64> key_buf; StringBuffer<64> key_len_buf; @@ -2417,7 +2585,8 @@ int Explain_update::print_explain(Explain_query *query, void Explain_update::print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze, - bool no_tmp_tbl) + bool no_tmp_tbl, + bool is_eliminated) { Json_writer_nesting_guard guard(writer); @@ -2602,7 +2771,8 @@ void Explain_update::print_explain_json(Explain_query *query, int Explain_insert::print_explain(Explain_query *query, select_result_sink *output, uint8 explain_flags, - bool is_analyze) + bool is_analyze, + bool is_eliminated) { const char *select_type="INSERT"; print_explain_row(output, explain_flags, is_analyze, @@ -2625,7 +2795,7 @@ int Explain_insert::print_explain(Explain_query *query, void Explain_insert::print_explain_json(Explain_query *query, Json_writer *writer, bool is_analyze, - bool no_tmp_tbl) + bool no_tmp_tbl, bool is_eliminated) { Json_writer_nesting_guard guard(writer); |