merging.

1 files changed, 65 insertions, 75 deletions

diff --git a/sql/sql_derived.cc b/sql/sql_derived.cc
index 9bfa49c5f2d..e012c161945 100644
--- a/sql/sql_derived.cc
+++ b/sql/sql_derived.cc
@@ -85,15 +85,18 @@ mysql_handle_derived(LEX *lex, uint phases)
 	   cursor && !res;
 	   cursor= cursor->next_local)
       {
+        if (!cursor->is_view_or_derived() && phases == DT_MERGE_FOR_INSERT)
+          continue;
         uint8 allowed_phases= (cursor->is_merged_derived() ? DT_PHASES_MERGE :
-                               DT_PHASES_MATERIALIZE);
+                               DT_PHASES_MATERIALIZE | DT_MERGE_FOR_INSERT);
         /*
           Skip derived tables to which the phase isn't applicable.
           TODO: mark derived at the parse time, later set it's type
           (merged or materialized)
         */
         if ((phase_flag != DT_PREPARE && !(allowed_phases & phase_flag)) ||
-            (cursor->merged_for_insert && phase_flag != DT_REINIT))
+            (cursor->merged_for_insert && phase_flag != DT_REINIT &&
+             phase_flag != DT_PREPARE))
           continue;
 	res= (*processors[phase])(lex->thd, lex, cursor);
       }
@@ -343,43 +346,52 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived)
   if (derived->merged)
     return FALSE;
 
+ if (thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
+     thd->lex->sql_command == SQLCOM_DELETE_MULTI)
+   thd->save_prep_leaf_list= TRUE;
+
   arena= thd->activate_stmt_arena_if_needed(&backup);  // For easier test
   derived->merged= TRUE;
-  /*
-    Check whether there is enough free bits in table map to merge subquery.
-    If not - materialize it. This check isn't cached so when there is a big
-    and small subqueries, and the bigger one can't be merged it wouldn't
-    block the smaller one.
-  */
-  if (parent_lex->get_free_table_map(&map, &tablenr))
-  {
-    /* There is no enough table bits, fall back to materialization. */
-    derived->change_refs_to_fields();
-    derived->set_materialized_derived();
-    goto exit_merge;
-  }
 
-  if (dt_select->leaf_tables.elements + tablenr > MAX_TABLES)
+  if (!derived->merged_for_insert || 
+      (derived->is_multitable() && 
+       (thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
+        thd->lex->sql_command == SQLCOM_DELETE_MULTI)))
   {
-    /* There is no enough table bits, fall back to materialization. */
-    derived->change_refs_to_fields();
-    derived->set_materialized_derived();
-    goto exit_merge;
-  }
+    /*
+      Check whether there is enough free bits in table map to merge subquery.
+      If not - materialize it. This check isn't cached so when there is a big
+      and small subqueries, and the bigger one can't be merged it wouldn't
+      block the smaller one.
+    */
+    if (parent_lex->get_free_table_map(&map, &tablenr))
+    {
+      /* There is no enough table bits, fall back to materialization. */
+      derived->change_refs_to_fields();
+      derived->set_materialized_derived();
+      goto exit_merge;
+    }
+
+    if (dt_select->leaf_tables.elements + tablenr > MAX_TABLES)
+    {
+      /* There is no enough table bits, fall back to materialization. */
+      derived->change_refs_to_fields();
+      derived->set_materialized_derived();
+      goto exit_merge;
+    }
 
-  if (dt_select->options & OPTION_SCHEMA_TABLE)
-    parent_lex->options |= OPTION_SCHEMA_TABLE;
+    if (dt_select->options & OPTION_SCHEMA_TABLE)
+      parent_lex->options |= OPTION_SCHEMA_TABLE;
 
-  parent_lex->cond_count+= dt_select->cond_count;
+    parent_lex->cond_count+= dt_select->cond_count;
 
-  if (!derived->get_unit()->prepared)
-  {
-    dt_select->leaf_tables.empty();
-    make_leaves_list(dt_select->leaf_tables, derived, TRUE, 0);
-  } 
+    if (!derived->get_unit()->prepared)
+    {
+      dt_select->leaf_tables.empty();
+      make_leaves_list(dt_select->leaf_tables, derived, TRUE, 0);
+    } 
 
-  if (!derived->merged_for_insert)
-  {  derived->nested_join= (NESTED_JOIN*) thd->calloc(sizeof(NESTED_JOIN));
+    derived->nested_join= (NESTED_JOIN*) thd->calloc(sizeof(NESTED_JOIN));
     if (!derived->nested_join)
     {
       res= TRUE;
@@ -387,7 +399,7 @@ bool mysql_derived_merge(THD *thd, LEX *lex, TABLE_LIST *derived)
     }
 
     /* Merge derived table's subquery in the parent select. */
-    if (parent_lex->merge_subquery(derived, dt_select, tablenr, map))
+    if (parent_lex->merge_subquery(thd, derived, dt_select, tablenr, map))
     {
       res= TRUE;
       goto exit_merge;
@@ -463,52 +475,21 @@ exit_merge:
 
 bool mysql_derived_merge_for_insert(THD *thd, LEX *lex, TABLE_LIST *derived)
 {
-  SELECT_LEX *dt_select= derived->get_single_select();
-
   if (derived->merged_for_insert)
     return FALSE;
-  /* It's a target view for an INSERT, create field translation only. */
-  if (!derived->updatable || derived->is_materialized_derived())
-  {
-    bool res= derived->create_field_translation(thd);
-    return res;
-  }
+  if (derived->is_materialized_derived())
+    return mysql_derived_prepare(thd, lex, derived);
   if (!derived->is_multitable())
   {
-    TABLE_LIST *tl=((TABLE_LIST*)dt_select->table_list.first);
-    TABLE *table= tl->table;
-    /* preserve old map & tablenr. */
-    if (!derived->merged_for_insert && derived->table)
-      table->set_table_map(derived->table->map, derived->table->tablenr);
-
-    derived->table= table;
-    derived->schema_table=
-      ((TABLE_LIST*)dt_select->table_list.first)->schema_table;
-    if (!derived->merged)
+    if (!derived->updatable)
+      return derived->create_field_translation(thd);
+    if (derived->merge_underlying_list)
     {
-      Query_arena *arena, backup;
-      arena= thd->activate_stmt_arena_if_needed(&backup);  // For easier test
-      derived->select_lex->leaf_tables.push_back(tl);
-      derived->nested_join= (NESTED_JOIN*) thd->calloc(sizeof(NESTED_JOIN));
-      if (derived->nested_join)
-      {
-        derived->wrap_into_nested_join(tl->select_lex->top_join_list);
-        derived->get_unit()->exclude_level(); 
-      }
-      if (arena)
-        thd->restore_active_arena(arena, &backup);
-      derived->merged= TRUE;
-      if (!derived->nested_join)
-        return TRUE;
-    }      
-  }
-  else
-  {
-    if (!derived->merged_for_insert && mysql_derived_merge(thd, lex, derived))
-      return TRUE;
-  }
-  derived->merged_for_insert= TRUE;
-
+      derived->table= derived->merge_underlying_list->table;
+      derived->schema_table= derived->merge_underlying_list->schema_table;
+      derived->merged_for_insert= TRUE;
+    }
+  }  
   return FALSE;
 }
 
@@ -609,7 +590,11 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
   bool res= FALSE;
 
   // Skip already prepared views/DT
-  if (!unit || unit->prepared || derived->merged_for_insert)
+  if (!unit || unit->prepared ||
+      (derived->merged_for_insert && 
+       !(derived->is_multitable() &&
+         (thd->lex->sql_command == SQLCOM_UPDATE_MULTI ||
+          thd->lex->sql_command == SQLCOM_DELETE_MULTI))))
     DBUG_RETURN(FALSE);
 
   Query_arena *arena= thd->stmt_arena, backup;
@@ -659,13 +644,18 @@ bool mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *derived)
     !unit->union_distinct->next_select() (i.e. it is union and last distinct
     SELECT is last SELECT of UNION).
   */
+  thd->create_tmp_table_for_derived= TRUE;
   if (derived->derived_result->create_result_table(thd, &unit->types, FALSE,
                                                 (first_select->options |
                                                  thd->options |
                                                  TMP_TABLE_ALL_COLUMNS),
                                                 derived->alias,
                                                 FALSE, FALSE))
+  { 
+    thd->create_tmp_table_for_derived= FALSE;
     goto exit;
+  }
+  thd->create_tmp_table_for_derived= FALSE;
 
   derived->table= derived->derived_result->table;
   if (derived->is_derived() && derived->is_merged_derived())
@@ -747,7 +737,7 @@ bool mysql_derived_optimize(THD *thd, LEX *lex, TABLE_LIST *derived)
 
   bool res= FALSE;
 
-  if (unit->optimized && !unit->uncacheable && !unit->describe)
+  if (unit->optimized)
     return FALSE;
   lex->current_select= first_select;