bzr commit into mysql-5.1-bugteam branch (Dmitry.Shulga:3527) Bug#11749345

[Dmitry Shulga]

#At file:///Users/shulga/projects/mysql/5.1-bugteam-bug38813/ based on revid:luis.soares@stripped

 3527 Dmitry Shulga	2011-04-11
      Fixed bug#11749345 (formerly #38813) - increasing memory consumption
      when selecting from I_S and views exist, in SP
      
      The problem was that when view is being opened its LEX is incorporated
      into SQL-statement's LEX.
      
      The solution is to create temporal LEX when make opening of tables.
     @ mysql-test/r/information_schema.result
        Previous result set for explain plan statement was invalid.

    modified:
      mysql-test/r/information_schema.result
      sql/sql_show.cc
=== modified file 'mysql-test/r/information_schema.result'
--- a/mysql-test/r/information_schema.result	2010-11-30 17:51:25 +0000
+++ b/mysql-test/r/information_schema.result	2011-04-11 09:41:32 +0000
@@ -1342,7 +1342,7 @@ id	select_type	table	type	possible_keys	
 1	SIMPLE	tables	ALL	NULL	NULL	NULL	NULL	NULL	Open_frm_only; Scanned all databases; Using filesort
 explain select * from (select table_name from information_schema.tables) as a;
 id	select_type	table	type	possible_keys	key	key_len	ref	rows	Extra
-1	PRIMARY	<derived2>	system	NULL	NULL	NULL	NULL	0	const row not found
+1	PRIMARY	<derived2>	ALL	NULL	NULL	NULL	NULL	54	
 2	DERIVED	tables	ALL	NULL	NULL	NULL	NULL	NULL	Skip_open_table; Scanned all databases
 drop view v1;
 create table t1 (f1 int(11));

=== modified file 'sql/sql_show.cc'
--- a/sql/sql_show.cc	2010-12-14 09:33:03 +0000
+++ b/sql/sql_show.cc	2011-04-11 09:41:32 +0000
@@ -3021,18 +3021,17 @@ make_table_name_list(THD *thd, List<LEX_
 static int 
 fill_schema_show_cols_or_idxs(THD *thd, TABLE_LIST *tables,
                               ST_SCHEMA_TABLE *schema_table,
-                              Open_tables_state *open_tables_state_backup)
+                              Open_tables_state *open_tables_state_backup,
+                              TABLE_LIST *show_table_list)
 {
   LEX *lex= thd->lex;
   bool res;
   LEX_STRING tmp_lex_string, tmp_lex_string1, *db_name, *table_name;
   enum_sql_command save_sql_command= lex->sql_command;
-  TABLE_LIST *show_table_list= tables->schema_select_lex->table_list.first;
   TABLE *table= tables->table;
   int error= 1;
   DBUG_ENTER("fill_schema_show");
 
-  lex->all_selects_list= tables->schema_select_lex;
   /*
     Restore thd->temporary_tables to be able to process
     temporary tables(only for 'show index' & 'show columns').
@@ -3300,7 +3299,6 @@ int get_all_tables(THD *thd, TABLE_LIST 
 {
   LEX *lex= thd->lex;
   TABLE *table= tables->table;
-  SELECT_LEX *old_all_select_lex= lex->all_selects_list;
   enum_sql_command save_sql_command= lex->sql_command;
   SELECT_LEX *lsel= tables->schema_select_lex;
   ST_SCHEMA_TABLE *schema_table= tables->schema_table;
@@ -3312,20 +3310,37 @@ int get_all_tables(THD *thd, TABLE_LIST 
   List<LEX_STRING> db_names;
   List_iterator_fast<LEX_STRING> it(db_names);
   COND *partial_cond= 0;
-  uint derived_tables= lex->derived_tables; 
   int error= 1;
   Open_tables_state open_tables_state_backup;
-  uint8 save_context_analysis_only= lex->context_analysis_only;
   Query_tables_list query_tables_list_backup;
 #ifndef NO_EMBEDDED_ACCESS_CHECKS
   Security_context *sctx= thd->security_ctx;
 #endif
+
   uint table_open_method;
+  MEM_ROOT mem_root_for_i_s;
+  Query_arena i_s_arena(&mem_root_for_i_s,
+                        Query_arena::CONVENTIONAL_EXECUTION),
+              backup_arena, *old_arena;
+  LEX *old_lex= thd->lex, temp_lex;
   DBUG_ENTER("get_all_tables");
 
-  lex->context_analysis_only|= CONTEXT_ANALYSIS_ONLY_VIEW;
+  // use dedicated MEM_ROOT
+  old_arena= thd->stmt_arena;
+  init_sql_alloc(&mem_root_for_i_s, MEM_ROOT_BLOCK_SIZE, 0);
+  thd->stmt_arena= &i_s_arena;
+  thd->lex= &temp_lex;
+  lex_start(thd);
+  lex= thd->lex;
+  lex->sql_command= old_lex->sql_command;
+  lex->wild= old_lex->wild;
+  lex->select_lex.db= old_lex->select_lex.db;
+
+  lex->context_analysis_only= CONTEXT_ANALYSIS_ONLY_VIEW;
   lex->reset_n_backup_query_tables_list(&query_tables_list_backup);
 
+  thd->set_n_backup_active_arena(&i_s_arena, &backup_arena);
+
   /*
     We should not introduce deadlocks even if we already have some
     tables open and locked, since we won't lock tables which we will
@@ -3340,8 +3355,24 @@ int get_all_tables(THD *thd, TABLE_LIST 
   */
   if (lsel && lsel->table_list.first)
   {
+    LEX_STRING db_name, table_name;
+    db_name.str= lsel->table_list.first->db;
+    db_name.length= strlen(db_name.str);
+
+    table_name.str= lsel->table_list.first->table_name;
+    table_name.length= strlen(table_name.str);
+
+    sel.parent_lex= lex;
+
+    if (make_table_list(thd, &sel, &db_name, &table_name))
+      goto err;
+
+    TABLE_LIST *show_table_list= sel.table_list.first;
+    lex->all_selects_list= &sel;
+    lex->derived_tables= 0;
     error= fill_schema_show_cols_or_idxs(thd, tables, schema_table,
-                                         &open_tables_state_backup);
+                                         &open_tables_state_backup,
+                                         show_table_list);
     goto err;
   }
 
@@ -3537,11 +3568,17 @@ int get_all_tables(THD *thd, TABLE_LIST 
   error= 0;
 err:
   thd->restore_backup_open_tables_state(&open_tables_state_backup);
-  lex->restore_backup_query_tables_list(&query_tables_list_backup);
-  lex->derived_tables= derived_tables;
-  lex->all_selects_list= old_all_select_lex;
-  lex->context_analysis_only= save_context_analysis_only;
-  lex->sql_command= save_sql_command;
+
+  lex_end(thd->lex);
+  thd->lex= old_lex;
+
+  if (i_s_arena.free_list)
+    i_s_arena.free_items();
+
+  free_root(&mem_root_for_i_s, MYF(0));
+  thd->stmt_arena= old_arena;
+  thd->restore_active_arena(&i_s_arena, &backup_arena);
+
   DBUG_RETURN(error);
 }
 


Attachment: [text/bzr-bundle] bzr/[e-mail]