Code cleanup.

sql/opt_qpf.cc

@@ -81,14 +81,13 @@ void QPF_query::add_node(QPF_node *node)
     QPF_select *sel= (QPF_select*)node;
     if (sel->select_id == (int)UINT_MAX)
     {
-      //TODO this is a "fake select" from a UNION.
-      DBUG_ASSERT(0);
+      DBUG_ASSERT(0); // this is a "fake select" from a UNION.
     }
     else
     {
       uint select_id= sel->select_id;
       QPF_select *old_node;
-      //DBUG_ASSERT(!get_select(select_id));
+
       if (selects.elements() <= select_id)
         selects.resize(max(select_id+1, selects.elements()*2), NULL);
 
@@ -115,7 +114,7 @@ int QPF_query::print_explain(select_result_sink *output,
   }
   else
   {
-    // Start printing from id=1
+    /* Start printing from node with id=1 */
     QPF_node *node= get_node(1);
     return node->print_explain(this, output, explain_flags);
   }
@@ -264,8 +263,6 @@ QPF_select::~QPF_select()
 int QPF_select::print_explain(QPF_query *query, select_result_sink *output,
                               uint8 explain_flags)
 {
-  //output->unit.offset_limit_cnt= 0; 
-
   if (message)
   {
     List<Item> item_list;
@@ -328,7 +325,6 @@ int QPF_table_access::print_explain(select_result_sink *output, uint8 explain_fl
 
   List<Item> item_list;
   Item *item_null= new Item_null();
-  //const CHARSET_INFO *cs= system_charset_info;
   
   if (sjm_nest_select_id)
     select_id= sjm_nest_select_id;

sql/opt_qpf.h

@@ -361,7 +361,7 @@ public:
   StringBuffer<32> used_partitions;
   bool used_partitions_set;
   
-  /* Empty strings means "NULL" will be printed */
+  /* Empty string means "NULL" will be printed */
   StringBuffer<32> possible_keys_str;
   
   /*
@@ -375,7 +375,8 @@ public:
   QPF_index_use key;
   
   /*
-    when type==JT_HASH_NEXT, this stores the real index.
+    when type==JT_HASH_NEXT, 'key' stores the hash join pseudo-key.
+    hash_next_key stores the table's key.
   */
   QPF_index_use hash_next_key;
   

sql/sql_delete.cc

@@ -51,7 +51,7 @@
     invoked on a running DELETE statement.
 */
 
-void Delete_plan::save_query_plan_footprint(QPF_query *query)
+void Delete_plan::save_qpf(QPF_query *query)
 {
   QPF_delete* qpf= new QPF_delete;
 
@@ -63,22 +63,22 @@ void Delete_plan::save_query_plan_footprint(QPF_query *query)
   else
   {
     qpf->deleting_all_rows= false;
-    Update_plan::save_query_plan_footprint_intern(query, qpf);
+    Update_plan::save_qpf_intern(query, qpf);
   }
 
   query->upd_del_plan= qpf;
 }
 
 
-void Update_plan::save_query_plan_footprint(QPF_query *query)
+void Update_plan::save_qpf(QPF_query *query)
 {
   QPF_update* qpf= new QPF_update;
-  save_query_plan_footprint_intern(query, qpf);
+  save_qpf_intern(query, qpf);
   query->upd_del_plan= qpf;
 }
 
 
-void Update_plan::save_query_plan_footprint_intern(QPF_query *query, QPF_update *qpf)
+void Update_plan::save_qpf_intern(QPF_query *query, QPF_update *qpf)
 {
   qpf->select_type= "SIMPLE";
   qpf->table_name.append(table->pos_in_table_list->alias);
@@ -116,7 +116,6 @@ void Update_plan::save_query_plan_footprint_intern(QPF_query *query, QPF_update
   qpf->using_where= test(select && select->cond);
   qpf->using_filesort= using_filesort;
 
-  //using_filesort is already set
   make_possible_keys_line(table, possible_keys, &qpf->possible_keys_line);
 
   /* Calculate key_len */
@@ -141,6 +140,7 @@ void Update_plan::save_query_plan_footprint_intern(QPF_query *query, QPF_update
   }
 
   bool skip= updating_a_view;
+
   /* Save subquery children */
   for (SELECT_LEX_UNIT *unit= select_lex->first_inner_unit();
        unit;
@@ -157,11 +157,6 @@ void Update_plan::save_query_plan_footprint_intern(QPF_query *query, QPF_update
     */
     if (!(unit->item && unit->item->eliminated))
       qpf->add_child(unit->first_select()->select_number);
-    
-    //TODO: temporary?:
-    //  A: yes. optimizing children subqueries has caused them to save QPFs,
-    //  automatically.
-    //unit->save_qpf(query);
   }
 }
 
@@ -423,7 +418,7 @@ bool mysql_delete(THD *thd, TABLE_LIST *table_list, COND *conds,
   if (thd->lex->describe)
     goto exit_without_my_ok;
 
-  query_plan.save_query_plan_footprint(thd->lex->query_plan_footprint);
+  query_plan.save_qpf(thd->lex->query_plan_footprint);
   thd->apc_target.enable();
 
   DBUG_EXECUTE_IF("show_explain_probe_delete_exec_start", 
@@ -656,7 +651,7 @@ cleanup:
   
   /* Special exits */
 exit_without_my_ok:
-  query_plan.save_query_plan_footprint(thd->lex->query_plan_footprint);
+  query_plan.save_qpf(thd->lex->query_plan_footprint);
 
   select_send *result2;
   if (!(result2= new select_send()))

sql/sql_lex.h

@@ -2397,8 +2397,8 @@ public:
   /* Set this plan to be a plan to do nothing because of impossible WHRE*/
   void set_impossible_where() { impossible_where= true; }
 
-  void save_query_plan_footprint(QPF_query *query);
-  void save_query_plan_footprint_intern(QPF_query *query, QPF_update *qpf);
+  void save_qpf(QPF_query *query);
+  void save_qpf_intern(QPF_query *query, QPF_update *qpf);
   virtual ~Update_plan() {}
 
   Update_plan() : impossible_where(false), using_filesort(false) {}
@@ -2422,7 +2422,7 @@ public:
     table_rows= rows_arg;
   }
 
-  void save_query_plan_footprint(QPF_query *query);
+  void save_qpf(QPF_query *query);
 };
 
 

sql/sql_select.cc

@@ -22517,8 +22517,6 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
                    bool distinct, const char *message)
 {
   QPF_node *qp_node;
-  const bool on_the_fly= true;
- 
   JOIN *join= this; /* Legacy: this code used to be a non-member function */
   THD *thd=join->thd;
   const CHARSET_INFO *cs= system_charset_info;
@@ -22535,7 +22533,7 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
   {
     QPF_select *qp_sel;
     qp_node= qp_sel= new (output->mem_root) QPF_select;
-    join->select_lex->set_explain_type(on_the_fly);
+    join->select_lex->set_explain_type(true);
 
     qp_sel->select_id= join->select_lex->select_number;
     qp_sel->select_type= join->select_lex->type;
@@ -22554,10 +22552,7 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
     qp_node= qp_sel= new (output->mem_root) QPF_select;
     table_map used_tables=0;
 
-    if (on_the_fly)
-      join->select_lex->set_explain_type(on_the_fly);
-
-    //bool printing_materialize_nest= FALSE;
+    join->select_lex->set_explain_type(true);
     uint select_id= join->select_lex->select_number;
 
     qp_sel->select_id= join->select_lex->select_number;
@@ -22568,13 +22563,6 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
     for (JOIN_TAB *tab= first_breadth_first_tab(join, WALK_OPTIMIZATION_TABS); tab;
          tab= next_breadth_first_tab(join, WALK_OPTIMIZATION_TABS, tab))
     {
-      if (tab->bush_root_tab)
-      {
-        JOIN_TAB *first_sibling= tab->bush_root_tab->bush_children->start;
-        select_id= first_sibling->emb_sj_nest->sj_subq_pred->get_identifier();
-        //printing_materialize_nest= TRUE;
-      }
-      
       TABLE *table=tab->table;
       TABLE_LIST *table_list= tab->table->pos_in_table_list;
       char buff4[512];
@@ -22615,9 +22603,6 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
         qpt->sjm_nest_select_id= 0;
 
       /* select_type */
-      //const char* stype= printing_materialize_nest? "MATERIALIZED" : 
-      //                                              join->select_lex->type;
-      //item_list.push_back(new Item_string(stype, strlen(stype), cs));
       qp_sel->select_type= join->select_lex->type;
 
       /* table */
@@ -22684,8 +22669,6 @@ int JOIN::save_qpf(QPF_query *output, bool need_tmp_table, bool need_order,
       append_possible_keys(&qpt->possible_keys_str, table, tab->keys);
 
       /* Build "key", "key_len", and "ref" */
-
-      // tmp4 holds ref
       if (tab_type == JT_NEXT)
       {
 	key_info= table->key_info+tab->index;

sql/sql_update.cc

@@ -500,7 +500,7 @@ int mysql_update(THD *thd,
   if (thd->lex->describe)
     goto exit_without_my_ok;
 
-  query_plan.save_query_plan_footprint(thd->lex->query_plan_footprint);
+  query_plan.save_qpf(thd->lex->query_plan_footprint);
   thd->apc_target.enable();
   apc_target_enabled= true;
   DBUG_EXECUTE_IF("show_explain_probe_update_exec_start", 
@@ -1031,10 +1031,9 @@ err:
 
 exit_without_my_ok:
   DBUG_ASSERT(!apc_target_enabled);
-  query_plan.save_query_plan_footprint(thd->lex->query_plan_footprint);
+  query_plan.save_qpf(thd->lex->query_plan_footprint);
   
   select_send *result;
-  //bool printed_anything;
   if (!(result= new select_send()))
     return 1;                               /* purecov: inspected */
   List<Item> dummy; /* note: looked in 5.6 and they too use a dummy list like this */