PS and SP made compatible in mechanism used for preparing query for rexecutions (Bug #2266)

mysql-test/r/sp.result

@@ -1305,3 +1305,13 @@ test	bar	PROCEDURE	root@localhost	0000-00-00 00:00:00	0000-00-00 00:00:00	DEFINE
 drop procedure bar|
 drop table t1;
 drop table t2;
+create procedure p1 () select (select s1 from t1) from t1;
+create table t1 (s1 int);
+call p1();
+(select s1 from t1)
+insert into t1 values (1);
+call p1();
+(select s1 from t1)
+1
+drop procedure p1;
+drop table t1;

mysql-test/t/sp.test

@@ -1444,3 +1444,15 @@ drop procedure bar|
 delimiter ;|
 drop table t1;
 drop table t2;
+
+#
+# rexecution
+#
+create procedure p1 () select (select s1 from t1) from t1;
+create table t1 (s1 int);
+call p1();
+insert into t1 values (1);
+call p1();
+drop procedure p1;
+drop table t1;
+

sql/item_subselect.cc

@@ -104,7 +104,7 @@ bool Item_subselect::fix_fields(THD *thd_param, TABLE_LIST *tables, Item **ref)
 {
   DBUG_ASSERT(fixed == 0);
   engine->set_thd((thd= thd_param));
-  stmt= thd->current_statement;
+  arena= thd->current_arena;
 
   char const *save_where= thd->where;
   int res= engine->prepare();
@@ -316,8 +316,8 @@ Item_singlerow_subselect::select_transformer(JOIN *join)
     if (join->conds || join->having)
     {
       Item *cond;
-      if (stmt)
-	thd->set_n_backup_item_arena(stmt, &backup);
+      if (arena)
+	thd->set_n_backup_item_arena(arena, &backup);
 
       if (!join->having)
 	cond= join->conds;
@@ -330,15 +330,15 @@ Item_singlerow_subselect::select_transformer(JOIN *join)
 					   new Item_null())))
 	goto err;
     }
-    if (stmt)
-      thd->restore_backup_item_arena(stmt, &backup);
+    if (arena)
+      thd->restore_backup_item_arena(arena, &backup);
     return RES_REDUCE;
   }
   return RES_OK;
   
 err:
-  if (stmt)
-    thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->restore_backup_item_arena(arena, &backup);
   return RES_ERROR;
 }
 
@@ -618,8 +618,8 @@ Item_in_subselect::single_value_transformer(JOIN *join,
   Statement backup;
 
   thd->where= "scalar IN/ALL/ANY subquery";
-  if (stmt)
-    thd->set_n_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->set_n_backup_item_arena(arena, &backup);
 
   if (select_lex->item_list.elements > 1)
   {
@@ -823,21 +823,21 @@ Item_in_subselect::single_value_transformer(JOIN *join,
 	  push_warning(thd, MYSQL_ERROR::WARN_LEVEL_NOTE,
 		       ER_SELECT_REDUCED, warn_buff);
 	}
-	if (stmt)
-	  thd->restore_backup_item_arena(stmt, &backup);
+	if (arena)
+	  thd->restore_backup_item_arena(arena, &backup);
 	DBUG_RETURN(RES_REDUCE);
       }
     }
   }
 
 ok:
-  if (stmt)
-    thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->restore_backup_item_arena(arena, &backup);
   DBUG_RETURN(RES_OK);
 
 err:
-  if (stmt)
-    thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->restore_backup_item_arena(arena, &backup);
   DBUG_RETURN(RES_ERROR);
 }
 
@@ -855,8 +855,8 @@ Item_in_subselect::row_value_transformer(JOIN *join)
   Item *item= 0;
 
   thd->where= "row IN/ALL/ANY subquery";
-  if (stmt)
-    thd->set_n_backup_item_arena(stmt, &backup);  
+  if (arena)
+    thd->set_n_backup_item_arena(arena, &backup);  
 
   SELECT_LEX *select_lex= join->select_lex;
 
@@ -940,13 +940,13 @@ Item_in_subselect::row_value_transformer(JOIN *join)
     if (join->conds->fix_fields(thd, join->tables_list, 0))
       goto err;
   }
-  if (stmt)
-    thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->restore_backup_item_arena(arena, &backup);
   DBUG_RETURN(RES_OK);
 
 err:
-  if (stmt)
-    thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->restore_backup_item_arena(arena, &backup);
   DBUG_RETURN(RES_ERROR);
 }
 

sql/item_subselect.h

@@ -26,7 +26,7 @@ class JOIN;
 class select_subselect;
 class subselect_engine;
 class Item_bool_func2;
-class Statement;
+class Item_arena;
 
 /* base class for subselects */
 
@@ -36,8 +36,8 @@ class Item_subselect :public Item_result_field
 protected:
   /* thread handler, will be assigned in fix_fields only */
   THD *thd;
-  /* prepared statement, or 0 */
-  Statement *stmt;
+  /* Item_arena used or 0 */
+  Item_arena *arena;
   /* substitution instead of subselect in case of optimization */
   Item *substitution;
   /* unit of subquery */

sql/item_sum.cc

@@ -77,15 +77,15 @@ Item_sum::Item_sum(THD *thd, Item_sum *item):
 */
 bool Item_sum::save_args_for_prepared_statements(THD *thd)
 {
-  if (thd->current_statement)
-    return save_args(thd->current_statement);
+  if (thd->current_arena && args_copy == 0)
+    return save_args(thd->current_arena);
   return 0;
 }
 
 
-bool Item_sum::save_args(Statement* stmt)
+bool Item_sum::save_args(Item_arena* arena)
 {
-  if (!(args_copy= (Item**) stmt->alloc(sizeof(Item*)*arg_count)))
+  if (!(args_copy= (Item**) arena->alloc(sizeof(Item*)*arg_count)))
     return 1;
   memcpy(args_copy, args, sizeof(Item*)*arg_count);
   return 0;

sql/item_sum.h

@@ -23,6 +23,8 @@
 
 #include <my_tree.h>
 
+class Item_arena;
+
 class Item_sum :public Item_result_field
 {
 public:
@@ -93,7 +95,7 @@ class Item_sum :public Item_result_field
   virtual void make_unique() {}
   Item *get_tmp_table_item(THD *thd);
   bool save_args_for_prepared_statements(THD *);
-  bool save_args(Statement* stmt);
+  bool save_args(Item_arena* stmt);
 
   bool walk (Item_processor processor, byte *argument);
 };

sql/mysql_priv.h

@@ -681,6 +681,7 @@ void mysql_stmt_reset(THD *thd, char *packet);
 void mysql_stmt_get_longdata(THD *thd, char *pos, ulong packet_length);
 int check_insert_fields(THD *thd,TABLE *table,List<Item> &fields,
 			List<Item> &values, ulong counter);
+void reset_stmt_for_execute(THD *thd, LEX *lex);
 
 /* sql_error.cc */
 MYSQL_ERROR *push_warning(THD *thd, MYSQL_ERROR::enum_warning_level level, uint code,

sql/sp_head.cc

@@ -186,8 +186,8 @@ sp_head::operator new(size_t size)
   bzero((char *)&own_root, sizeof(own_root));
   init_alloc_root(&own_root, MEM_ROOT_BLOCK_SIZE, MEM_ROOT_PREALLOC);
   sp= (sp_head *)alloc_root(&own_root, size);
-  sp->m_mem_root= own_root;
-  
+  sp->mem_root= own_root;
+  DBUG_PRINT("info", ("mem_root 0x%lx", (ulong) &sp->mem_root));
   DBUG_RETURN(sp);
 }
 
@@ -198,16 +198,18 @@ sp_head::operator delete(void *ptr, size_t size)
   MEM_ROOT own_root;
   sp_head *sp= (sp_head *)ptr;
 
-  DBUG_PRINT("info", ("root: %lx", &sp->m_mem_root));
-  memcpy(&own_root, (const void *)&sp->m_mem_root, sizeof(MEM_ROOT));
+  memcpy(&own_root, (const void *)&sp->mem_root, sizeof(MEM_ROOT));
+  DBUG_PRINT("info", ("mem_root 0x%lx moved to 0x%lx",
+                      (ulong) &sp->mem_root, (ulong) &own_root));
   free_root(&own_root, MYF(0));
 
   DBUG_VOID_RETURN;
 }
 
+
 sp_head::sp_head()
-  : Sql_alloc(), m_returns_cs(NULL), m_has_return(FALSE), m_simple_case(FALSE),
-    m_multi_results(FALSE), m_free_list(NULL)
+  :Item_arena((bool)FALSE), m_returns_cs(NULL), m_has_return(FALSE),
+   m_simple_case(FALSE), m_multi_results(FALSE)
 {
   DBUG_ENTER("sp_head::sp_head");
 
@@ -216,6 +218,7 @@ sp_head::sp_head()
   DBUG_VOID_RETURN;
 }
 
+
 void
 sp_head::init(LEX *lex)
 {
@@ -359,7 +362,7 @@ sp_head::destroy()
     delete i;
   delete_dynamic(&m_instr);
   m_pcont->destroy();
-  free_items(m_free_list);
+  free_items(free_list);
   while ((lex= (LEX *)m_lex.pop()))
   {
     if (lex != &m_thd->main_lex) // We got interrupted and have lex'es left
@@ -392,6 +395,7 @@ sp_head::execute(THD *thd)
   if (ctx)
     ctx->clear_handler();
   thd->query_error= 0;
+  thd->current_arena= this;
   do
   {
     sp_instr *i;
@@ -430,6 +434,9 @@ sp_head::execute(THD *thd)
  done:
   DBUG_PRINT("info", ("ret=%d killed=%d query_error=%d",
 		      ret, thd->killed, thd->query_error));
+  if (thd->current_arena)
+    cleanup_items(thd->current_arena->free_list);
+  thd->current_arena= 0;
   if (thd->killed || thd->query_error || thd->net.report_error)
     ret= -1;
   /* If the DB has changed, the pointer has changed too, but the
@@ -687,21 +694,6 @@ sp_head::restore_lex(THD *thd)
   // Update some state in the old one first
   oldlex->ptr= sublex->ptr;
   oldlex->next_state= sublex->next_state;
-  for (sl= sublex->all_selects_list ;
-       sl ;
-       sl= sl->next_select_in_list())
-  {
-    // Save WHERE clause pointers to avoid damaging by optimisation
-    sl->prep_where= sl->where;
-    if (sl->with_wild)
-    {
-      // Copy item_list. We will restore it before calling the
-      // sub-statement, so it's ok to pop them.
-      sl->item_list_copy.empty();
-      while (Item *it= sl->item_list.pop())
-	sl->item_list_copy.push_back(it);
-    }
-  }
 
   // Collect some data from the sub statement lex.
   sp_merge_funs(oldlex, sublex);
@@ -792,19 +784,19 @@ sp_head::set_info(char *definer, uint definerlen,
   if (! p)
     p= definer;		// Weird...
   len= p-definer;
-  m_definer_user.str= strmake_root(&m_mem_root, definer, len);
+  m_definer_user.str= strmake_root(&mem_root, definer, len);
   m_definer_user.length= len;
   len= definerlen-len-1;
-  m_definer_host.str= strmake_root(&m_mem_root, p+1, len);
+  m_definer_host.str= strmake_root(&mem_root, p+1, len);
   m_definer_host.length= len;
   m_created= created;
   m_modified= modified;
-  m_chistics= (st_sp_chistics *)alloc_root(&m_mem_root, sizeof(st_sp_chistics));
+  m_chistics= (st_sp_chistics *)alloc_root(&mem_root, sizeof(st_sp_chistics));
   memcpy(m_chistics, chistics, sizeof(st_sp_chistics));
   if (m_chistics->comment.length == 0)
     m_chistics->comment.str= 0;
   else
-    m_chistics->comment.str= strmake_root(&m_mem_root,
+    m_chistics->comment.str= strmake_root(&mem_root,
 					  m_chistics->comment.str,
 					  m_chistics->comment.length);
 }
@@ -812,26 +804,33 @@ sp_head::set_info(char *definer, uint definerlen,
 void
 sp_head::reset_thd_mem_root(THD *thd)
 {
+  DBUG_ENTER("sp_head::reset_thd_mem_root");
   m_thd_root= thd->mem_root;
-  thd->mem_root= m_mem_root;
-  m_free_list= thd->free_list; // Keep the old list
+  thd->mem_root= mem_root;
+  DBUG_PRINT("info", ("mem_root 0x%lx moved to thd mem root 0x%lx",
+                      (ulong) &mem_root, (ulong) &thd->mem_root));
+  free_list= thd->free_list; // Keep the old list
   thd->free_list= NULL;	// Start a new one
   /* Copy the db, since substatements will point to it */
   m_thd_db= thd->db;
   thd->db= strmake_root(&thd->mem_root, thd->db, thd->db_length);
   m_thd= thd;
+  DBUG_VOID_RETURN;
 }
 
 void
 sp_head::restore_thd_mem_root(THD *thd)
 {
-  Item *flist= m_free_list;	// The old list
-  m_free_list= thd->free_list; // Get the new one
+  DBUG_ENTER("sp_head::restore_thd_mem_root");
+  Item *flist= free_list;	// The old list
+  set_item_arena(thd);          // Get new fre_list and mem_root
+  DBUG_PRINT("info", ("mem_root 0x%lx returned from thd mem root 0x%lx",
+                      (ulong) &mem_root, (ulong) &thd->mem_root));
   thd->free_list= flist;	// Restore the old one
   thd->db= m_thd_db;		// Restore the original db pointer
-  m_mem_root= thd->mem_root;
   thd->mem_root= m_thd_root;
   m_thd= NULL;
+  DBUG_VOID_RETURN;
 }
 
 
@@ -919,7 +918,6 @@ int
 sp_instr_stmt::exec_stmt(THD *thd, LEX *lex)
 {
   LEX *olex;			// The other lex
-  Item *freelist;
   SELECT_LEX *sl;
   int res;
 
@@ -927,94 +925,24 @@ sp_instr_stmt::exec_stmt(THD *thd, LEX *lex)
   thd->lex= lex;		// Use my own lex
   thd->lex->thd = thd;		// QQ Not reentrant!
   thd->lex->unit.thd= thd;	// QQ Not reentrant
-  freelist= thd->free_list;
   thd->free_list= NULL;
 
   VOID(pthread_mutex_lock(&LOCK_thread_count));
   thd->query_id= query_id++;
   VOID(pthread_mutex_unlock(&LOCK_thread_count));
 
-  // Copy WHERE clause pointers to avoid damaging by optimisation
-  // Also clear ref_pointer_arrays.
-  for (sl= lex->all_selects_list ;
-       sl ;
-       sl= sl->next_select_in_list())
-  {
-    if (lex->sql_command == SQLCOM_CREATE_TABLE ||
-	lex->sql_command == SQLCOM_INSERT_SELECT)
-    {				// Destroys sl->table_list.first
-      sl->table_list_first_copy= sl->table_list.first;
-    }
-    if (sl->with_wild)
-    {
-      // Restore item_list
-      // Note: We have to do this before executing the sub-statement,
-      //       to make sure that the list nodes are in the right
-      //       memroot.
-      List_iterator_fast<Item> li(sl->item_list_copy);
-
-      sl->item_list.empty();
-      while (Item *it= li++)
-	sl->item_list.push_back(it);
-    }
-    sl->ref_pointer_array= 0;
-    if (sl->prep_where)
-      sl->where= sl->prep_where->copy_andor_structure(thd);
-    for (ORDER *order= (ORDER *)sl->order_list.first ;
-	 order ;
-	 order= order->next)
-    {
-      order->item_copy= order->item;
-    }
-    for (ORDER *group= (ORDER *)sl->group_list.first ;
-	 group ;
-	 group= group->next)
-    {
-      group->item_copy= group->item;
-    }
-  }
+  reset_stmt_for_execute(thd, lex);
 
   res= mysql_execute_command(thd);
 
+  lex->unit.cleanup();
   if (thd->lock || thd->open_tables || thd->derived_tables)
   {
     thd->proc_info="closing tables";
     close_thread_tables(thd);			/* Free tables */
   }
 
-  for (sl= lex->all_selects_list ;
-       sl ;
-       sl= sl->next_select_in_list())
-  {
-    TABLE_LIST *tabs;
-
-    if (lex->sql_command == SQLCOM_CREATE_TABLE ||
-	lex->sql_command == SQLCOM_INSERT_SELECT)
-    {				// Restore sl->table_list.first
-      sl->table_list.first= sl->table_list_first_copy;
-    }
-    // We have closed all tables, get rid of pointers to them
-    for (tabs=(TABLE_LIST *)sl->table_list.first ;
-	 tabs ;
-	 tabs= tabs->next)
-    {
-      tabs->table= NULL;
-    }
-    for (ORDER *order= (ORDER *)sl->order_list.first ;
-	 order ;
-	 order= order->next)
-    {
-      order->item= order->item_copy;
-    }
-    for (ORDER *group= (ORDER *)sl->group_list.first ;
-	 group ;
-	 group= group->next)
-    {
-      group->item= group->item_copy;
-    }
-  }
   thd->lex= olex;		// Restore the other lex
-  thd->free_list= freelist;
 
   return res;
 }

sql/sp_head.h

@@ -70,7 +70,7 @@ sp_name *
 sp_name_current_db_new(THD *thd, LEX_STRING name);
 
 
-class sp_head : public Sql_alloc
+class sp_head :private Item_arena
 {
   sp_head(const sp_head &);	/* Prevent use of these */
   void operator=(sp_head &);
@@ -206,9 +206,7 @@ class sp_head : public Sql_alloc
 
 private:
 
-  MEM_ROOT m_mem_root;		// My own mem_root
   MEM_ROOT m_thd_root;		// Temp. store for thd's mem_root
-  Item *m_free_list;		// Where the items go
   THD *m_thd;			// Set if we have reset mem_root
   char *m_thd_db;		// Original thd->db pointer
 

sql/sql_base.cc

@@ -2158,14 +2158,14 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
 {
   if (!wild_num)
     return 0;
-  Statement *stmt= thd->current_statement, backup;
+  Item_arena *arena= thd->current_arena, backup;
 
   /*
     If we are in preparing prepared statement phase then we have change
     temporary mem_root to statement mem root to save changes of SELECT list
   */
-  if (stmt)
-    thd->set_n_backup_item_arena(stmt, &backup);
+  if (arena)
+    thd->set_n_backup_item_arena(arena, &backup);
   reg2 Item *item;
   List_iterator<Item> it(fields);
   while ( wild_num && (item= it++))
@@ -2178,8 +2178,8 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
       if (insert_fields(thd,tables,((Item_field*) item)->db_name,
 			((Item_field*) item)->table_name, &it))
       {
-	if (stmt)
-	  thd->restore_backup_item_arena(stmt, &backup);
+	if (arena)
+	  thd->restore_backup_item_arena(arena, &backup);
 	return (-1);
       }
       if (sum_func_list)
@@ -2194,8 +2194,15 @@ int setup_wild(THD *thd, TABLE_LIST *tables, List<Item> &fields,
       wild_num--;
     }
   }
-  if (stmt)
-      thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+  {
+    /* make * substituting permanent */
+    SELECT_LEX *select_lex= thd->lex->current_select;
+    select_lex->with_wild= 0;
+    select_lex->item_list= fields;
+
+    thd->restore_backup_item_arena(arena, &backup);
+  }
   return 0;
 }
 
@@ -2408,12 +2415,17 @@ insert_fields(THD *thd,TABLE_LIST *tables, const char *db_name,
 int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
 {
   table_map not_null_tables= 0;
-  Statement *stmt= thd->current_statement, backup;
-
+  SELECT_LEX *select_lex= thd->lex->current_select;
+  Item_arena *arena= ((thd->current_arena && 
+                       !select_lex->conds_processed_with_permanent_arena) ?
+                      thd->current_arena :
+                      0);
+  Item_arena backup;
   DBUG_ENTER("setup_conds");
+
   thd->set_query_id=1;
   
-  thd->lex->current_select->cond_count= 0;
+  select_lex->cond_count= 0;
   if (*conds)
   {
     thd->where="where clause";
@@ -2436,7 +2448,7 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
 	  table->on_expr->fix_fields(thd, tables, &table->on_expr) ||
 	  table->on_expr->check_cols(1))
 	DBUG_RETURN(1);
-      thd->lex->current_select->cond_count++;
+      select_lex->cond_count++;
 
       /*
 	If it's a normal join or a LEFT JOIN which can be optimized away
@@ -2447,12 +2459,12 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
 	   !(specialflag & SPECIAL_NO_NEW_FUNC)))
       {
 	table->outer_join= 0;
-	if (stmt)
-	  thd->set_n_backup_item_arena(stmt, &backup);
+	if (arena)
+	  thd->set_n_backup_item_arena(arena, &backup);
 	*conds= and_conds(*conds, table->on_expr);
 	table->on_expr=0;
-	if (stmt)
-	  thd->restore_backup_item_arena(stmt, &backup);
+	if (arena)
+	  thd->restore_backup_item_arena(arena, &backup);
 	if ((*conds) && !(*conds)->fixed &&
 	    (*conds)->fix_fields(thd, tables, conds))
 	  DBUG_RETURN(1);
@@ -2460,8 +2472,8 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
     }
     if (table->natural_join)
     {
-      if (stmt)
-	thd->set_n_backup_item_arena(stmt, &backup);
+      if (arena)
+	thd->set_n_backup_item_arena(arena, &backup);
       /* Make a join of all fields with have the same name */
       TABLE *t1= table->table;
       TABLE *t2= table->natural_join->table;
@@ -2491,7 +2503,7 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
           t2->used_keys.intersect(t2_field->part_of_key);
         }
       }
-      thd->lex->current_select->cond_count+= cond_and->list.elements;
+      select_lex->cond_count+= cond_and->list.elements;
 
       // to prevent natural join processing during PS re-execution
       table->natural_join= 0;
@@ -2500,8 +2512,8 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
       {
 	*conds= and_conds(*conds, cond_and);
 	// fix_fields() should be made with temporary memory pool
-	if (stmt)
-	  thd->restore_backup_item_arena(stmt, &backup);
+	if (arena)
+	  thd->restore_backup_item_arena(arena, &backup);
 	if (*conds && !(*conds)->fixed)
 	{
 	  if ((*conds)->fix_fields(thd, tables, conds))
@@ -2512,8 +2524,8 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
       {
 	table->on_expr= and_conds(table->on_expr, cond_and);
 	// fix_fields() should be made with temporary memory pool
-	if (stmt)
-	  thd->restore_backup_item_arena(stmt, &backup);
+	if (arena)
+	  thd->restore_backup_item_arena(arena, &backup);
 	if (table->on_expr && !table->on_expr->fixed)
 	{
 	  if (table->on_expr->fix_fields(thd, tables, &table->on_expr))
@@ -2523,21 +2535,22 @@ int setup_conds(THD *thd,TABLE_LIST *tables,COND **conds)
     }
   }
 
-  if (stmt)
+  if (arena)
   {
     /*
       We are in prepared statement preparation code => we should store
       WHERE clause changing for next executions.
 
-      We do this ON -> WHERE transformation only once per PS statement.
+      We do this ON -> WHERE transformation only once per PS/SP statement.
     */
-    thd->lex->current_select->where= *conds;
+    select_lex->where= *conds;
+    select_lex->conds_processed_with_permanent_arena= 1;
   }
   DBUG_RETURN(test(thd->net.report_error));
 
 err:
-  if (stmt)
-      thd->restore_backup_item_arena(stmt, &backup);
+  if (arena)
+      thd->restore_backup_item_arena(arena, &backup);
   DBUG_RETURN(1);
 }
 

sql/sql_class.cc

@@ -86,7 +86,7 @@ extern "C" void free_user_var(user_var_entry *entry)
 ** Thread specific functions
 ****************************************************************************/
 
-THD::THD():user_time(0), current_statement(0), is_fatal_error(0),
+THD::THD():user_time(0), current_arena(0), is_fatal_error(0),
 	   last_insert_id_used(0),
 	   insert_id_used(0), rand_used(0), in_lock_tables(0),
 	   global_read_lock(0), bootstrap(0), spcont(NULL)
@@ -1210,23 +1210,47 @@ int select_dumpvar::prepare(List<Item> &list, SELECT_LEX_UNIT *u)
 }
 
 
+Item_arena::Item_arena(THD* thd)
+  :free_list(0)
+{
+  init_sql_alloc(&mem_root,
+                 thd->variables.query_alloc_block_size,
+                 thd->variables.query_prealloc_size);
+}
+
+
+Item_arena::Item_arena()
+  :free_list(0)
+{
+  bzero((char *) &mem_root, sizeof(mem_root));
+}
+
+
+Item_arena::Item_arena(bool init_mem_root)
+  :free_list(0)
+{
+  if (init_mem_root)
+    bzero((char *) &mem_root, sizeof(mem_root));
+}
+
+
+Item_arena::~Item_arena()
+{}
+
+
 /*
   Statement functions 
 */
 
 Statement::Statement(THD *thd)
-  :id(++thd->statement_id_counter),
+  :Item_arena(thd),
+  id(++thd->statement_id_counter),
   set_query_id(1),
   allow_sum_func(0),
   lex(&main_lex),
   query(0),
-  query_length(0),
-  free_list(0)
-{
-  init_sql_alloc(&mem_root,
-                 thd->variables.query_alloc_block_size,
-                 thd->variables.query_prealloc_size);
-}
+  query_length(0)
+{}
 
 /*
   This constructor is called when statement is a subobject of THD:
@@ -1235,15 +1259,14 @@ Statement::Statement(THD *thd)
 */
 
 Statement::Statement()
-  :id(0),
+  :Item_arena(),
+  id(0),
   set_query_id(1),
   allow_sum_func(0),                            /* initialized later */
   lex(&main_lex),
   query(0),                                     /* these two are set */ 
-  query_length(0),                              /* in alloc_query() */
-  free_list(0)
+  query_length(0)                               /* in alloc_query() */
 {
-  bzero((char *) &mem_root, sizeof(mem_root));
 }
 
 
@@ -1264,14 +1287,14 @@ void Statement::set_statement(Statement *stmt)
 }
 
 
-void Statement::set_n_backup_item_arena(Statement *set, Statement *backup)
+void Item_arena::set_n_backup_item_arena(Item_arena *set, Item_arena *backup)
 {
   backup->set_item_arena(this);
   set_item_arena(set);
 }
 
 
-void Statement::restore_backup_item_arena(Statement *set, Statement *backup)
+void Item_arena::restore_backup_item_arena(Item_arena *set, Item_arena *backup)
 {
   set->set_item_arena(this);
   set_item_arena(backup);
@@ -1279,7 +1302,7 @@ void Statement::restore_backup_item_arena(Statement *set, Statement *backup)
   init_alloc_root(&backup->mem_root, 0, 0);
 }
 
-void Statement::set_item_arena(Statement *set)
+void Item_arena::set_item_arena(Item_arena *set)
 {
   mem_root= set->mem_root;
   free_list= set->free_list;

sql/sql_class.h

@@ -434,6 +434,48 @@ struct system_variables
 void free_tmp_table(THD *thd, TABLE *entry);
 
 
+class Item_arena
+{
+public:
+  /*
+    List of items created in the parser for this query. Every item puts
+    itself to the list on creation (see Item::Item() for details))
+  */
+  Item *free_list;
+  MEM_ROOT mem_root;
+  
+  Item_arena(THD *thd);
+  Item_arena();
+  Item_arena(bool init_mem_root);
+  ~Item_arena();
+
+  inline gptr alloc(unsigned int size) { return alloc_root(&mem_root,size); }
+  inline gptr calloc(unsigned int size)
+  {
+    gptr ptr;
+    if ((ptr=alloc_root(&mem_root,size)))
+      bzero((char*) ptr,size);
+    return ptr;
+  }
+  inline char *strdup(const char *str)
+  { return strdup_root(&mem_root,str); }
+  inline char *strmake(const char *str, uint size)
+  { return strmake_root(&mem_root,str,size); }
+  inline char *memdup(const char *str, uint size)
+  { return memdup_root(&mem_root,str,size); }
+  inline char *memdup_w_gap(const char *str, uint size, uint gap)
+  {
+    gptr ptr;
+    if ((ptr=alloc_root(&mem_root,size+gap)))
+      memcpy(ptr,str,size);
+    return ptr;
+  }
+
+  void set_n_backup_item_arena(Item_arena *set, Item_arena *backup);
+  void restore_backup_item_arena(Item_arena *set, Item_arena *backup);
+  void set_item_arena(Item_arena *set);
+};
+
 /*
   State of a single command executed against this connection.
   One connection can contain a lot of simultaneously running statements,
@@ -448,7 +490,7 @@ void free_tmp_table(THD *thd, TABLE *entry);
   be used explicitly.
 */
 
-class Statement
+class Statement: public Item_arena
 {
   Statement(const Statement &rhs);              /* not implemented: */
   Statement &operator=(const Statement &rhs);   /* non-copyable */
@@ -489,12 +531,6 @@ class Statement
   */
   char *query;
   uint32 query_length;                          // current query length
-  /*
-    List of items created in the parser for this query. Every item puts
-    itself to the list on creation (see Item::Item() for details))
-  */
-  Item *free_list;
-  MEM_ROOT mem_root;
 
 public:
   /* We build without RTTI, so dynamic_cast can't be used. */
@@ -518,31 +554,6 @@ class Statement
   /* return class type */
   virtual Type type() const;
 
-  inline gptr alloc(unsigned int size) { return alloc_root(&mem_root,size); }
-  inline gptr calloc(unsigned int size)
-  {
-    gptr ptr;
-    if ((ptr=alloc_root(&mem_root,size)))
-      bzero((char*) ptr,size);
-    return ptr;
-  }
-  inline char *strdup(const char *str)
-  { return strdup_root(&mem_root,str); }
-  inline char *strmake(const char *str, uint size)
-  { return strmake_root(&mem_root,str,size); }
-  inline char *memdup(const char *str, uint size)
-  { return memdup_root(&mem_root,str,size); }
-  inline char *memdup_w_gap(const char *str, uint size, uint gap)
-  {
-    gptr ptr;
-    if ((ptr=alloc_root(&mem_root,size+gap)))
-      memcpy(ptr,str,size);
-    return ptr;
-  }
-
-  void set_n_backup_item_arena(Statement *set, Statement *backup);
-  void restore_backup_item_arena(Statement *set, Statement *backup);
-  void set_item_arena(Statement *set);
 };
 
 
@@ -746,9 +757,9 @@ class THD :public ilink,
   Vio* active_vio;
 #endif
   /*
-    Current prepared Statement if there one, or 0
+    Current prepared Item_arena if there one, or 0
   */
-  Statement *current_statement;
+  Item_arena *current_arena;
   /*
     next_insert_id is set on SET INSERT_ID= #. This is used as the next
     generated auto_increment value in handler.cc
@@ -969,7 +980,7 @@ class THD :public ilink,
 
   inline void allocate_temporary_memory_pool_for_ps_preparing()
   {
-    DBUG_ASSERT(current_statement!=0);
+    DBUG_ASSERT(current_arena!=0);
     /*
       We do not want to have in PS memory all that junk,
       which will be created by preparation => substitute memory
@@ -978,7 +989,7 @@ class THD :public ilink,
       We know that PS memory pool is now copied to THD, we move it back
       to allow some code use it.
     */
-    current_statement->set_item_arena(this);
+    current_arena->set_item_arena(this);
     init_sql_alloc(&mem_root,
 		   variables.query_alloc_block_size,
 		   variables.query_prealloc_size);
@@ -986,12 +997,16 @@ class THD :public ilink,
   }
   inline void free_temporary_memory_pool_for_ps_preparing()
   {
-    DBUG_ASSERT(current_statement!=0);
-    cleanup_items(current_statement->free_list);
+    DBUG_ASSERT(current_arena!=0);
+    cleanup_items(current_arena->free_list);
     free_items(free_list);
     close_thread_tables(this); // to close derived tables
     free_root(&mem_root, MYF(0));
-    set_item_arena(current_statement);
+    set_item_arena(current_arena);
+  }
+  inline bool only_prepare()
+  {
+    return command == COM_PREPARE;
   }
 };
 

sql/sql_delete.cc

@@ -264,10 +264,11 @@ int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
 {
   TABLE_LIST *delete_table_list= ((TABLE_LIST*) thd->lex->
 				  select_lex.table_list.first);
+  SELECT_LEX *select_lex= &thd->lex->select_lex;
   DBUG_ENTER("mysql_prepare_delete");
 
   if (setup_conds(thd, delete_table_list, conds) || 
-      setup_ftfuncs(&thd->lex->select_lex))
+      setup_ftfuncs(select_lex))
     DBUG_RETURN(-1);
   if (find_real_table_in_list(table_list->next, 
 			      table_list->db, table_list->real_name))
@@ -275,6 +276,11 @@ int mysql_prepare_delete(THD *thd, TABLE_LIST *table_list, Item **conds)
     my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->real_name);
     DBUG_RETURN(-1);
   }
+  if (thd->current_arena && select_lex->first_execution)
+  {
+    select_lex->prep_where= select_lex->where;
+    select_lex->first_execution= 0;
+  }
   DBUG_RETURN(0);
 }
 

sql/sql_derived.cc

@@ -152,7 +152,7 @@ static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit,
     if it is preparation PS only then we do not need real data and we
     can skip execution (and parameters is not defined, too)
   */
-  if (!thd->current_statement)
+  if (!thd->only_prepare())
   {
     if (is_union)
     {

sql/sql_insert.cc

@@ -460,6 +460,7 @@ int mysql_prepare_insert(THD *thd, TABLE_LIST *table_list,
     my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->real_name);
     DBUG_RETURN(-1);
   }
+  thd->lex->select_lex.first_execution= 0;
   DBUG_RETURN(0);
 }
 

sql/sql_lex.cc

@@ -1011,10 +1011,12 @@ void st_select_lex::init_query()
   having_fix_field= 0;
   resolve_mode= NOMATTER_MODE;
   cond_count= with_wild= 0;
+  conds_processed_with_permanent_arena= 0;
   ref_pointer_array= 0;
   select_n_having_items= 0;
   prep_where= 0;
   explicit_limit= 0;
+  first_execution= 1;
 }
 
 void st_select_lex::init_select()
@@ -1414,7 +1416,9 @@ bool st_select_lex::add_order_to_list(THD *thd, Item *item, bool asc)
 
 bool st_select_lex::add_item_to_list(THD *thd, Item *item)
 {
-  return item_list.push_back(item);
+  DBUG_ENTER("st_select_lex::add_item_to_list");
+  DBUG_PRINT("info", ("Item: %p", item));
+  DBUG_RETURN(item_list.push_back(item));
 }
 
 
@@ -1500,9 +1504,9 @@ bool st_select_lex::setup_ref_array(THD *thd, uint order_group_num)
     We have to create array in prepared statement memory if it is
     prepared statement
   */
-  Statement *stmt= thd->current_statement ? thd->current_statement : thd;
+  Item_arena *arena= thd->current_arena ? thd->current_arena : thd;
   return (ref_pointer_array= 
-	  (Item **)stmt->alloc(sizeof(Item*) *
+          (Item **)arena->alloc(sizeof(Item*) *
                                 (item_list.elements +
                                  select_n_having_items +
                                  order_group_num)* 5)) == 0;

sql/sql_lex.h

@@ -405,8 +405,6 @@ class st_select_lex: public st_select_lex_node
   enum olap_type olap;
   SQL_LIST	      table_list, group_list;   /* FROM & GROUP BY clauses */
   List<Item>          item_list; /* list of fields & expressions */
-  List<Item>          item_list_copy; /* For SPs */
-  byte                *table_list_first_copy; /* For SPs */
   List<String>        interval_list, use_index, *use_index_ptr,
 		      ignore_index, *ignore_index_ptr;
   /* 
@@ -435,6 +433,11 @@ class st_select_lex: public st_select_lex_node
   uint cond_count;      /* number of arguments of and/or/xor in where/having */
   enum_parsing_place parsing_place; /* where we are parsing expression */
   bool with_sum_func;   /* sum function indicator */
+  /* 
+    PS or SP cond natural joins was alredy processed with permanent
+    arena and all additional items which we need alredy stored in it
+  */
+  bool conds_processed_with_permanent_arena;
 
   ulong table_join_options;
   uint in_sum_expr;
@@ -445,6 +448,7 @@ class st_select_lex: public st_select_lex_node
   bool having_fix_field;
   /* explicit LIMIT clause was used */
   bool explicit_limit;
+  bool first_execution; /* first execution in SP or PS */
 
   /* 
      SELECT for SELECT command st_select_lex. Used to privent scaning

sql/sql_parse.cc

@@ -4182,12 +4182,14 @@ void mysql_parse(THD *thd, char *inBuf, uint length)
 	  query_cache_end_of_result(thd);
 	}
       }
+      lex->unit.cleanup();
     }
     else
     {
       DBUG_PRINT("info",("Command aborted. Fatal_error: %d",
 			 thd->is_fatal_error));
       query_cache_abort(&thd->net);
+      lex->unit.cleanup();
       if (thd->lex->sphead)
       {
 	/* Clean up after failed stored procedure/function */

sql/sql_prepare.cc

@@ -1357,7 +1357,7 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
 
   mysql_log.write(thd, COM_PREPARE, "%s", packet);
 
-  thd->current_statement= stmt;
+  thd->current_arena= stmt;
   lex= lex_start(thd, (uchar *) thd->query, thd->query_length);
   mysql_init_query(thd);
   lex->safe_to_cache_query= 0;
@@ -1381,7 +1381,7 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
   stmt->set_item_arena(thd);
   thd->set_statement(&thd->stmt_backup);
   thd->set_item_arena(&thd->stmt_backup);
-  thd->current_statement= 0;
+  thd->current_arena= 0;
 
   if (error)
   {
@@ -1389,29 +1389,18 @@ void mysql_stmt_prepare(THD *thd, char *packet, uint packet_length)
     thd->stmt_map.erase(stmt);
     /* error is sent inside yyparse/send_prepare_results */
   }
-  else
-  {
-    SELECT_LEX *sl= stmt->lex->all_selects_list;
-    /*
-      Save WHERE clause pointers, because they may be changed during query
-      optimisation.
-    */
-    for (; sl; sl= sl->next_select_in_list())
-    {
-      sl->prep_where= sl->where;
-    }
-  }
   DBUG_VOID_RETURN;
 }
 
 /* Reinit statement before execution */
 
-static void reset_stmt_for_execute(Prepared_statement *stmt)
+void reset_stmt_for_execute(THD *thd, LEX *lex)
 {
-  THD *thd= stmt->thd;
-  SELECT_LEX *sl= stmt->lex->all_selects_list;
+  SELECT_LEX *sl= lex->all_selects_list;
 
   for (; sl; sl= sl->next_select_in_list())
+  {
+    if (!sl->first_execution)
     {
       /*
         Copy WHERE clause pointers to avoid damaging they by optimisation
@@ -1426,6 +1415,7 @@ static void reset_stmt_for_execute(Prepared_statement *stmt)
       /* Fix ORDER list */
       for (order= (ORDER *)sl->order_list.first; order; order= order->next)
         order->item= &order->item_ptr;
+    }
 
     /*
       TODO: When the new table structure is ready, then have a status bit 
@@ -1443,7 +1433,6 @@ static void reset_stmt_for_execute(Prepared_statement *stmt)
       tables->table= 0;
       tables->table_list= 0;
     }
-    
     {
       SELECT_LEX_UNIT *unit= sl->master_unit();
       unit->unclean();
@@ -1506,7 +1495,7 @@ void mysql_stmt_execute(THD *thd, char *packet, uint packet_length)
 
   thd->stmt_backup.set_statement(thd);
   thd->set_statement(stmt);
-  reset_stmt_for_execute(stmt);
+  reset_stmt_for_execute(thd, stmt->lex);
 #ifndef EMBEDDED_LIBRARY
   if (stmt->param_count)
   {

sql/sql_select.cc

@@ -367,9 +367,16 @@ JOIN::prepare(Item ***rref_pointer_array,
       Item_subselect::trans_res res;
       if ((res= subselect->select_transformer(this)) !=
 	  Item_subselect::RES_OK)
+      {
+        if (thd->current_arena && select_lex->first_execution)
+        {
+          select_lex->prep_where= select_lex->where;
+          select_lex->first_execution= 0;
+        }
 	DBUG_RETURN((res == Item_subselect::RES_ERROR));
       }
     }
+  }
 
   if (setup_ftfuncs(select_lex)) /* should be after having->fix_fields */
     DBUG_RETURN(-1);
@@ -470,6 +477,11 @@ JOIN::prepare(Item ***rref_pointer_array,
   if (alloc_func_list())
     goto err;
 
+  if (thd->current_arena && select_lex->first_execution)
+  {
+    select_lex->prep_where= select_lex->where;
+    select_lex->first_execution= 0;
+  }
   DBUG_RETURN(0); // All OK
 
 err:

sql/sql_union.cc

@@ -262,27 +262,32 @@ int st_select_lex_unit::prepare(THD *thd_arg, select_result *sel_result,
     thd_arg->lex->current_select= lex_select_save;
     if (!item_list.elements)
     {
-      Statement *stmt= thd->current_statement;
-      Statement backup;
-      if (stmt)
-	thd->set_n_backup_item_arena(stmt, &backup);
+      Item_arena *arena= thd->current_arena;
+      Item_arena backup;
+      if (arena)
+	thd->set_n_backup_item_arena(arena, &backup);
       Field **field;
       for (field= table->field; *field; field++)
       {
 	Item_field *item= new Item_field(*field);
 	if (!item || item_list.push_back(item))
 	{
-	  if (stmt)
-	    thd->restore_backup_item_arena(stmt, &backup);
+	  if (arena)
+	    thd->restore_backup_item_arena(arena, &backup);
 	  DBUG_RETURN(-1);
 	}
       }
-      if (stmt)
+      if (arena)
       {
-	thd->restore_backup_item_arena(stmt, &backup);
+	thd->restore_backup_item_arena(arena, &backup);
 
 	/* prepare fake select to initialize it correctly */
 	ulong options_tmp= init_prepare_fake_select_lex(thd);
+        /*
+          it should be done only once (because item_list builds only onece
+          per statement)
+        */
+        DBUG_ASSERT(fake_select_lex->join == 0);
 	if (!(fake_select_lex->join= new JOIN(thd, item_list, thd->options,
 					      result)))
 	{

sql/sql_update.cc

@@ -425,6 +425,7 @@ int mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
   TABLE *table= table_list->table;
   TABLE_LIST tables;
   List<Item> all_fields;
+  SELECT_LEX *select_lex= &thd->lex->select_lex;
   DBUG_ENTER("mysql_prepare_update");
 
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
@@ -437,10 +438,10 @@ int mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
 
   if (setup_tables(update_table_list) ||
       setup_conds(thd, update_table_list, conds) ||
-      thd->lex->select_lex.setup_ref_array(thd, order_num) ||
-      setup_order(thd, thd->lex->select_lex.ref_pointer_array,
+      select_lex->setup_ref_array(thd, order_num) ||
+      setup_order(thd, select_lex->ref_pointer_array,
 		  update_table_list, all_fields, all_fields, order) ||
-      setup_ftfuncs(&thd->lex->select_lex))
+      setup_ftfuncs(select_lex))
     DBUG_RETURN(-1);
 
   /* Check that we are not using table that we are updating in a sub select */
@@ -450,6 +451,11 @@ int mysql_prepare_update(THD *thd, TABLE_LIST *table_list,
     my_error(ER_UPDATE_TABLE_USED, MYF(0), table_list->real_name);
     DBUG_RETURN(-1);
   }
+  if (thd->current_arena && select_lex->first_execution)
+  {
+    select_lex->prep_where= select_lex->where;
+    select_lex->first_execution= 0;
+  }
 
   DBUG_RETURN(0);
 }