From 45f41b52e8f27e52388bb5e3fb6fbe4d93de161d Mon Sep 17 00:00:00 2001 From: Sergey Vojtovich Date: Thu, 21 May 2015 12:30:41 +0400 Subject: [PATCH] MDEV-8199 - first_breadth_first_tab() takes 0.07% in OLTP RO Split first_breadth_first_tab() into JOIN::first_breadth_first_optimization_tab() and JOIN::first_breadth_first_execution_tab(). This allows to eliminate function call and one condition. Adjusted callers accordingly. Overhead change: first_breadth_first_tab() 0.07% -> out of radar next_breadth_first_tab() 0.04% -> 0.04% JOIN::cleanup() 0.15% -> 0.11% JOIN::save_explain_data_intern() 0.28% -> 0.24% --- sql/sql_select.cc | 61 +++++++++++++++++++++-------------------------- sql/sql_select.h | 2 ++ 2 files changed, 29 insertions(+), 34 deletions(-) diff --git a/sql/sql_select.cc b/sql/sql_select.cc index bb96400edaf..41132b3efba 100644 --- a/sql/sql_select.cc +++ b/sql/sql_select.cc @@ -277,7 +277,6 @@ JOIN_TAB *first_depth_first_tab(JOIN* join); JOIN_TAB *next_depth_first_tab(JOIN* join, JOIN_TAB* tab); enum enum_exec_or_opt {WALK_OPTIMIZATION_TABS , WALK_EXECUTION_TABS}; -JOIN_TAB *first_breadth_first_tab(JOIN *join, enum enum_exec_or_opt tabs_kind); JOIN_TAB *next_breadth_first_tab(JOIN *join, enum enum_exec_or_opt tabs_kind, JOIN_TAB *tab); static double table_cond_selectivity(JOIN *join, uint idx, JOIN_TAB *s, @@ -7202,7 +7201,7 @@ double JOIN::get_examined_rows() { double examined_rows; double prev_fanout= 1; - JOIN_TAB *tab= first_breadth_first_tab(this, WALK_OPTIMIZATION_TABS); + JOIN_TAB *tab= first_breadth_first_optimization_tab(); JOIN_TAB *prev_tab= tab; examined_rows= tab->get_examined_rows(); @@ -8201,21 +8200,23 @@ prev_record_reads(POSITION *positions, uint idx, table_map found_ref) Enumerate join tabs in breadth-first fashion, including const tables. */ -JOIN_TAB *first_breadth_first_tab(JOIN *join, enum enum_exec_or_opt tabs_kind) -{ - /* There's always one (i.e. first) table */ - return (tabs_kind == WALK_EXECUTION_TABS)? join->join_tab: - join->table_access_tabs; -} - - JOIN_TAB *next_breadth_first_tab(JOIN *join, enum enum_exec_or_opt tabs_kind, JOIN_TAB *tab) { - JOIN_TAB* const first_top_tab= first_breadth_first_tab(join, tabs_kind); - const uint n_top_tabs_count= (tabs_kind == WALK_EXECUTION_TABS)? - join->top_join_tab_count: - join->top_table_access_tabs_count; + JOIN_TAB *first_top_tab; + uint n_top_tabs_count; + + if (tabs_kind == WALK_EXECUTION_TABS) + { + first_top_tab= join->first_breadth_first_execution_tab(); + n_top_tabs_count= join->top_join_tab_count; + } + else + { + first_top_tab= join->first_breadth_first_optimization_tab(); + n_top_tabs_count= join->top_table_access_tabs_count; + } + if (!tab->bush_root_tab) { /* We're at top level. Get the next top-level tab */ @@ -11800,27 +11801,19 @@ void JOIN::cleanup(bool full) w/o tables: they don't have some members initialized and WALK_OPTIMIZATION_TABS may not work correctly for them. */ - enum enum_exec_or_opt tabs_kind; - if (first_breadth_first_tab(this, WALK_OPTIMIZATION_TABS)) - tabs_kind= WALK_OPTIMIZATION_TABS; - else - tabs_kind= WALK_EXECUTION_TABS; if (table_count) { - for (tab= first_breadth_first_tab(this, tabs_kind); tab; - tab= next_breadth_first_tab(this, tabs_kind, tab)) - { + for (tab= first_breadth_first_optimization_tab(); tab; + tab= next_breadth_first_tab(this, WALK_OPTIMIZATION_TABS, tab)) tab->cleanup(); - } - if (tabs_kind == WALK_OPTIMIZATION_TABS && - first_breadth_first_tab(this, WALK_OPTIMIZATION_TABS) != - first_breadth_first_tab(this, WALK_EXECUTION_TABS)) + /* We've walked optimization tabs, do execution ones too. */ + if (first_breadth_first_execution_tab() != + first_breadth_first_optimization_tab()) { - JOIN_TAB *jt= first_breadth_first_tab(this, WALK_EXECUTION_TABS); - /* We've walked optimization tabs. do execution ones too */ - if (jt) - jt->cleanup(); + for (tab= first_breadth_first_execution_tab(); tab; + tab= next_breadth_first_tab(this, WALK_EXECUTION_TABS, tab)) + tab->cleanup(); } } cleaned= true; @@ -23556,13 +23549,13 @@ int append_possible_keys(MEM_ROOT *alloc, String_list &list, TABLE *table, void JOIN_TAB::update_explain_data(uint idx) { - if (this == first_breadth_first_tab(join, WALK_OPTIMIZATION_TABS) + join->const_tables && + if (this == join->first_breadth_first_optimization_tab() + join->const_tables && join->select_lex->select_number != INT_MAX && join->select_lex->select_number != UINT_MAX) { Explain_table_access *eta= new (join->thd->mem_root) Explain_table_access(join->thd->mem_root); - JOIN_TAB* const first_top_tab= first_breadth_first_tab(join, WALK_OPTIMIZATION_TABS); - save_explain_data(eta, join->const_table_map, join->select_distinct, first_top_tab); + save_explain_data(eta, join->const_table_map, join->select_distinct, + join->first_breadth_first_optimization_tab()); Explain_select *sel= join->thd->lex->explain->get_select(join->select_lex->select_number); idx -= my_count_bits(join->eliminated_tables); @@ -24059,7 +24052,7 @@ int JOIN::save_explain_data_intern(Explain_query *output, bool need_tmp_table, xpl_sel->exec_const_cond= exec_const_cond; - JOIN_TAB* const first_top_tab= first_breadth_first_tab(join, WALK_OPTIMIZATION_TABS); + JOIN_TAB* const first_top_tab= join->first_breadth_first_optimization_tab(); JOIN_TAB* prev_bush_root_tab= NULL; Explain_basic_join *cur_parent= xpl_sel; diff --git a/sql/sql_select.h b/sql/sql_select.h index 6621e4e9928..9cb7e0e61b1 100644 --- a/sql/sql_select.h +++ b/sql/sql_select.h @@ -1531,6 +1531,8 @@ public: int save_explain_data_intern(Explain_query *output, bool need_tmp_table, bool need_order, bool distinct, const char *message); + JOIN_TAB *first_breadth_first_optimization_tab() { return table_access_tabs; } + JOIN_TAB *first_breadth_first_execution_tab() { return join_tab; } private: /** TRUE if the query contains an aggregate function but has no GROUP