Simplified the code that fills recursive tables.

sql/sql_cte.cc

@@ -248,22 +248,32 @@ bool With_clause::check_anchors()
     if (!with_elem->is_recursive)
       continue;
 
-    table_map with_elem_dep= with_elem->derived_dep_map;
+    if (!with_elem->next_mutually_recursive)
-    table_map with_elem_map= with_elem->get_elem_map();
-    for (With_element *elem= with_elem;
-         elem != NULL;
-	 elem= elem->next_elem)
     {
-      if (!elem->is_recursive)
+      With_element *last_mutually_recursive= with_elem;
-        continue;
+      table_map with_elem_dep= with_elem->derived_dep_map;
+      table_map with_elem_map= with_elem->get_elem_map();
+      for (With_element *elem= with_elem;
+           elem != NULL;
+	   elem= elem->next_elem)
+      {
+        if (!elem->is_recursive)
+          continue;
 
-      if (elem == with_elem ||
+        if (elem == with_elem ||
-	  ((elem->derived_dep_map & with_elem_map) &&
+	    ((elem->derived_dep_map & with_elem_map) &&
-	   (with_elem_dep & elem->get_elem_map())))
+	     (with_elem_dep & elem->get_elem_map())))
 	{        
+          elem->next_mutually_recursive= with_elem;
+          last_mutually_recursive->next_mutually_recursive= elem;
+          last_mutually_recursive= elem;
 	  with_elem->mutually_recursive|= elem->get_elem_map();
-	  elem->mutually_recursive|= with_elem_map;
 	}
+      }
+      for (With_element *elem= with_elem->next_mutually_recursive;
+           elem != with_elem; 
+           elem=  elem->next_mutually_recursive)
+	elem->mutually_recursive= with_elem->mutually_recursive;
     }
  
     for (st_select_lex *sl= with_elem->spec->first_select();

sql/sql_cte.h

@@ -39,6 +39,7 @@ private:
   table_map work_dep_map;  // dependency map used for work
   /* Dependency map of with elements mutually recursive with this with element */
   table_map mutually_recursive; 
+  With_element *next_mutually_recursive;
   /* 
     Total number of references to this element in the FROM lists of
     the queries that are in the scope of the element (including
@@ -88,16 +89,20 @@ public:
 
   TABLE *result_table;
  
+  TABLE *first_rec_table_to_update;
+
 
   With_element(LEX_STRING *name,
                List <LEX_STRING> list,
                st_select_lex_unit *unit)
     : next_elem(NULL), base_dep_map(0), derived_dep_map(0),
       sq_dep_map(0), work_dep_map(0), mutually_recursive(0),
+      next_mutually_recursive(NULL), 
       references(0), table(NULL),
       query_name(name), column_list(list), spec(unit),
       is_recursive(false), with_anchor(false),
-      level(0), rec_result(NULL), result_table(NULL)
+    level(0), rec_result(NULL), result_table(NULL),
+    first_rec_table_to_update(NULL)
   {}
 
   bool check_dependencies_in_spec(THD *thd);
@@ -146,6 +151,9 @@ public:
 
   table_map get_mutually_recursive() { return mutually_recursive; }
 
+  With_element *get_next_mutually_recursive()
+  { return next_mutually_recursive; }
+
   void set_table(TABLE *tab) { table= tab; }
 
   TABLE *get_table() { return table; }
@@ -166,22 +174,6 @@ public:
 
   void reset_for_exec();
 
-  bool no_driving_recursive_is_set();
-
-  void set_as_driving_recursive();
-
-  bool is_driving_recursive();
-
-  void cleanup_driving_recursive();
-
-  void cleanup_incr_ready();
-
-  void set_as_incr_ready();
-
-  bool is_incr_ready();
-
-  bool all_incr_are_ready();
-
   void cleanup_stabilized();
 
   void set_as_stabilized();
@@ -228,8 +220,6 @@ private:
   table_map unrestricted;
   table_map with_prepared_anchor;
   table_map cleaned;
-  table_map driving_recursive;
-  table_map incr_ready;
   table_map stabilized;
 
 public:
@@ -241,7 +231,7 @@ public:
       embedding_with_clause(emb_with_clause), next_with_clause(NULL),
       dependencies_are_checked(false),
       unrestricted(0), with_prepared_anchor(0), cleaned(0),
-      driving_recursive(0), incr_ready(0), stabilized(0),
+      stabilized(0),
       with_recursive(recursive_fl)
   { last_next= &first_elem; }
 
@@ -331,68 +321,11 @@ void With_element::reset_for_exec()
   level= 0;
   owner->with_prepared_anchor&= ~mutually_recursive;
   owner->cleaned&= ~get_elem_map();
-  owner->driving_recursive&= ~get_elem_map();
+  first_rec_table_to_update= NULL;
-  cleanup_incr_ready();
   cleanup_stabilized();
 }
 
 
-inline
-bool With_element::no_driving_recursive_is_set()
-{
-  return !(owner->driving_recursive & mutually_recursive);
-}
-
-
-inline
-void With_element::set_as_driving_recursive()
-{
-  owner->driving_recursive|= get_elem_map();
-}
-
-
-inline
-bool With_element::is_driving_recursive()
-{
-  return owner->driving_recursive & get_elem_map();
-}
-
-
-inline
-void With_element::cleanup_driving_recursive()
-{
-  owner->driving_recursive&= ~mutually_recursive;
-}
-
-
-inline
-void With_element::cleanup_incr_ready()
-{
-  owner->incr_ready&= ~mutually_recursive;
-}
-
-
-inline
-void With_element::set_as_incr_ready()
-{
-  owner->incr_ready|= get_elem_map();
-}
-
-
-inline
-bool With_element::is_incr_ready()
-{
-  return owner->incr_ready & get_elem_map();
-}
-
-
-inline
-bool With_element::all_incr_are_ready()
-{
-  return (owner->incr_ready & mutually_recursive) == mutually_recursive;
-}
-
-
 inline
 void With_element::cleanup_stabilized()
 {

sql/sql_derived.cc

@@ -663,7 +663,6 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
       if (derived->is_with_table_recursive_reference())
       {
         unit->with_element->rec_result->rec_tables.push_back(derived->table);
-        derived->table->is_rec_table= true;
       }
     }
     DBUG_ASSERT(derived->table || res);
@@ -921,6 +920,28 @@ bool mysql_derived_create(THD *thd, LEX *lex, TABLE_LIST *derived)
 }
 
 
+bool TABLE_LIST::fill_recursive(THD *thd)
+{
+  bool rc= false;
+  st_select_lex_unit *unit= get_unit();
+  if (is_with_table_recursive_reference())
+    rc= unit->exec_recursive(false);
+  else
+  {
+    while(!with->all_are_stabilized() && !rc)
+    {
+      rc= unit->exec_recursive(true);
+    }
+    if (!rc)
+    {
+      TABLE *src= with->rec_result->table;
+      rc =src->insert_all_rows_into(thd, table, true);
+    } 
+  }
+  return rc;
+}
+
+
 /*
   Execute subquery of a materialized derived table/view and fill the result
   table.
@@ -944,6 +965,7 @@ bool mysql_derived_create(THD *thd, LEX *lex, TABLE_LIST *derived)
   @return TRUE   Error
 */
 
+
 bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
 {
   DBUG_ENTER("mysql_derived_fill");
@@ -951,14 +973,6 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
   bool derived_is_recursive= derived->is_recursive_with_table();
   bool res= FALSE;
 
-  if (derived_is_recursive && derived->with->all_are_stabilized())
-  {
-    TABLE *src= unit->with_element->rec_result->table;
-    TABLE *dest= derived->table;
-    res= src->insert_all_rows_into(thd, dest, true);
-    DBUG_RETURN(res);
-  }
-
   if (unit->executed && !unit->uncacheable && !unit->describe &&
       !derived_is_recursive)
     DBUG_RETURN(FALSE);
@@ -967,11 +981,14 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
   SELECT_LEX *first_select= unit->first_select();
   select_union *derived_result= derived->derived_result;
   SELECT_LEX *save_current_select= lex->current_select;
-  if (unit->is_union() || derived_is_recursive)
+  
+  if (derived_is_recursive)
+  {
+    res= derived->fill_recursive(thd);
+  }
+  else if (unit->is_union())
   {
     // execute union without clean up
-    if (derived_is_recursive)
-      unit->with_element->set_result_table(derived->table);
     res= unit->exec();
   }
   else
@@ -995,15 +1012,13 @@ bool mysql_derived_fill(THD *thd, LEX *lex, TABLE_LIST *derived)
                       derived_result, unit, first_select);
   }
 
-  if (!res)
+  if (!res && !derived_is_recursive)
   {
     if (derived_result->flush())
       res= TRUE;
     unit->executed= TRUE;
   }
-  if (res ||
+  if (res || (!lex->describe && !derived_is_recursive)) 
-      (!lex->describe &&
-       !(unit->with_element && unit->with_element->is_recursive))) 
     unit->cleanup();
   lex->current_select= save_current_select;
 

sql/sql_lex.h

@@ -704,7 +704,7 @@ public:
   bool prepare(THD *thd, select_result *result, ulong additional_options);
   bool optimize();
   bool exec();
-  bool exec_recursive();
+  bool exec_recursive(bool is_driving_recursive);
   bool cleanup();
   inline void unclean() { cleaned= 0; }
   void reinit_exec_mechanism();

sql/sql_select.cc

@@ -11606,11 +11606,7 @@ bool JOIN_TAB::preread_init()
 
   /* Materialize derived table/view. */
   if ((!derived->get_unit()->executed  ||
-       (derived->is_recursive_with_table() &&
+       derived->is_recursive_with_table()) &&
-        (!derived->is_with_table_recursive_reference() ||
-         (!derived->with->is_driving_recursive() &&
-          !derived->with->is_incr_ready()) &&
-	 !derived->with->all_are_stabilized()))) &&
       mysql_handle_single_derived(join->thd->lex,
                                     derived, DT_CREATE | DT_FILL))
       return TRUE;
@@ -18241,8 +18237,7 @@ sub_select(JOIN *join,JOIN_TAB *join_tab,bool end_of_records)
     flush_dups_table->sj_weedout_delete_rows();
   }
 
-  if ((!join_tab->preread_init_done || join_tab->table->is_rec_table) &&
+  if (!join_tab->preread_init_done && join_tab->preread_init())
-      join_tab->preread_init())
     DBUG_RETURN(NESTED_LOOP_ERROR);
 
   join->return_tab= join_tab;
@@ -19195,8 +19190,7 @@ int join_init_read_record(JOIN_TAB *tab)
     report_error(tab->table, error);
     return 1;
   }
-  if ((!tab->preread_init_done || tab->table->is_rec_table) &&
+  if (!tab->preread_init_done  && tab->preread_init())
-      tab->preread_init())
     return 1;
   if (init_read_record(&tab->read_record, tab->join->thd, tab->table,
                        tab->select, tab->filesort_result, 1,1, FALSE))
@@ -19429,8 +19423,6 @@ end_send(JOIN *join, JOIN_TAB *join_tab __attribute__((unused)),
 
   if (!end_of_records)
   {
-#if 0    
-#endif
     if (join->table_count &&
         join->join_tab->is_using_loose_index_scan())
     {

sql/sql_union.cc

@@ -244,7 +244,6 @@ select_union_recursive::create_result_table(THD *thd_arg,
 
   if (rec_tables.push_back(rec_table))
     return true;
-  rec_table->is_rec_table= true;
 
   return false;
 }
@@ -918,9 +917,8 @@ bool st_select_lex_unit::exec()
   bool first_execution= !executed;
   DBUG_ENTER("st_select_lex_unit::exec");
   bool was_executed= executed;
-  bool is_recursive= with_element && with_element->is_recursive;
 
-  if (executed && !uncacheable && !describe && !is_recursive)
+  if (executed && !uncacheable && !describe)
     DBUG_RETURN(FALSE);
   executed= 1;
   if (!(uncacheable & ~UNCACHEABLE_EXPLAIN) && item)
@@ -936,12 +934,6 @@ bool st_select_lex_unit::exec()
   if (saved_error)
     DBUG_RETURN(saved_error);
 
-  if (is_recursive && !describe)
-  {
-    saved_error= exec_recursive();
-    DBUG_RETURN(saved_error);
-  }
-
   if (uncacheable || !item || !item->assigned() || describe)
   {
     if (!fake_select_lex && !(with_element && with_element->is_recursive))
@@ -1168,107 +1160,95 @@ err:
 
 
 
-bool st_select_lex_unit::exec_recursive()
+bool st_select_lex_unit::exec_recursive(bool is_driving_recursive)
 {
   st_select_lex *lex_select_save= thd->lex->current_select;
-  st_select_lex *first_recursive_sel= with_element->first_recursive;
+  st_select_lex *start= with_element->first_recursive;
   TABLE *incr_table= with_element->rec_result->incr_table;
-  TABLE *result_table= with_element->result_table;
+  st_select_lex *end= NULL;
-  ha_rows examined_rows= 0;
+  bool is_unrestricted= with_element->is_unrestricted();
-  bool unrestricted= with_element->is_unrestricted();
-  bool with_anchor= with_element->with_anchor;
-  uint max_level= thd->variables.max_recursion_level;
   List_iterator_fast<TABLE> li(with_element->rec_result->rec_tables);
+  ha_rows examined_rows= 0;
+  bool was_executed= executed;
   TABLE *rec_table;
 
   DBUG_ENTER("st_select_lex_unit::exec_recursive");
 
-  do
+  executed= 1;
+  create_explain_query_if_not_exists(thd->lex, thd->mem_root);
+  if (!was_executed)
+    save_union_explain(thd->lex->explain);
+
+  if ((saved_error= incr_table->file->ha_delete_all_rows()))
+    goto err;
+
+  if (is_driving_recursive)
   {
-    st_select_lex *first_sl;
+    With_element *with_elem= with_element;
-    st_select_lex *barrier;
+    while ((with_elem= with_elem->get_next_mutually_recursive()) !=
-    if ((saved_error= incr_table->file->ha_delete_all_rows()))
+            with_element)
-      goto err;
-
-    if (with_element->no_driving_recursive_is_set())
-        with_element->set_as_driving_recursive();
-
-    if (with_element->level == 0)
     {
-      first_sl= first_select();
+      rec_table= with_elem->first_rec_table_to_update;
-      if (with_anchor)
+      if (rec_table)
-        barrier= first_recursive_sel;
+        rec_table->reginfo.join_tab->preread_init_done= false;        
-      else
-	barrier= NULL;
     }
-    else
-    {
-      first_sl= first_recursive_sel;
-      barrier= NULL;
-    }
-
-    if (with_element->all_incr_are_ready())
-      with_element->cleanup_incr_ready();
-   
-    for (st_select_lex *sl= first_sl ; sl != barrier; sl= sl->next_select())
-    {
-      thd->lex->current_select= sl;
-      sl->join->exec();
-      saved_error= sl->join->error;
-      if (!saved_error)
-      {
-         examined_rows+= thd->get_examined_row_count();
-         thd->set_examined_row_count(0);
-         if (union_result->flush())
-         {
-	   thd->lex->current_select= lex_select_save;
-	   DBUG_RETURN(1);
-         }
-      }
-      if (saved_error)
-      {
-        thd->lex->current_select= lex_select_save;
-        goto err;
-      }
-    }
-
-    with_element->set_as_incr_ready();
-
-    incr_table->file->info(HA_STATUS_VARIABLE);
-    if (incr_table->file->stats.records == 0 ||
-        with_element->level + 1 == max_level)
-      with_element->set_as_stabilized();
-    else
-      with_element->level++;
-
-    li.rewind();
-    while ((rec_table= li++))
-    {
-      if ((saved_error= incr_table->insert_all_rows_into(thd, rec_table,
-                                                         !unrestricted)))
-	  goto err;
-    }
-    
-    if (!with_element->is_driving_recursive())
-      break;
-
-  } while (!with_element->all_are_stabilized()); 
-
-  if (with_element->is_driving_recursive())
-  {
-    TABLE *table= with_element->rec_result->table;
-    if ((saved_error= table->insert_all_rows_into(thd,
-                                                  result_table,
-                                                  true)))
-      goto err;
-    with_element->cleanup_driving_recursive();
   }
 
+  if (with_element->level == 0)
+  {
+    start= first_select();
+    if (with_element->with_anchor)
+      end= with_element->first_recursive;
+  }
+   
+  for (st_select_lex *sl= start ; sl != end; sl= sl->next_select())
+  {
+    thd->lex->current_select= sl;
+    sl->join->exec();
+    saved_error= sl->join->error;
+    if (!saved_error)
+    {
+       examined_rows+= thd->get_examined_row_count();
+       thd->set_examined_row_count(0);
+       if (union_result->flush())
+       {
+	 thd->lex->current_select= lex_select_save;
+	 DBUG_RETURN(1);
+       }
+    }
+    if (saved_error)
+    {
+      thd->lex->current_select= lex_select_save;
+      goto err;
+      
+    }
+  }
+
+  thd->inc_examined_row_count(examined_rows);
+
+  incr_table->file->info(HA_STATUS_VARIABLE);
+  if (incr_table->file->stats.records == 0)
+    with_element->set_as_stabilized();
+  else
+    with_element->level++;
+
+  while ((rec_table= li++))
+  {
+    saved_error=
+      incr_table->insert_all_rows_into(thd, rec_table, !is_unrestricted);
+    if (!with_element->first_rec_table_to_update)
+      with_element->first_rec_table_to_update= rec_table;
+    if (with_element->level == 1)
+      rec_table->reginfo.join_tab->preread_init_done= true;  
+  }
+    
+  if (with_element->level == thd->variables.max_recursion_level)
+    with_element->set_as_stabilized();
+
   thd->lex->current_select= lex_select_save;
 err:
   thd->lex->set_limit_rows_examined();
   DBUG_RETURN(saved_error);    
-    
 }
 
 

sql/table.h

@@ -1244,7 +1244,6 @@ public:
   bool alias_name_used;              /* true if table_name is alias */
   bool get_fields_in_item_tree;      /* Signal to fix_field */
   bool m_needs_reopen;
-  bool is_rec_table;
 private:
   bool created;    /* For tmp tables. TRUE <=> tmp table was actually created.*/
 public:
@@ -2234,6 +2233,7 @@ struct TABLE_LIST
   bool is_with_table();
   bool is_recursive_with_table();
   bool is_with_table_recursive_reference();
+  bool fill_recursive(THD *thd);
 
   inline void set_view()
   {