new lock for multiupdate:

- open and create derived tables
- detect which tables should be locked for write
- lock and fill derived tables
some unitialized variables fixed

mysql-test/r/lock_multi.result

@@ -26,7 +26,7 @@ lock table t1 read;
  update t1,t2 set c=a where b=d;
 select c from t2;
 c
-1
+2
 drop table t1;
 drop table t2;
 create table t1 (a int);

mysql-test/r/multi_update.result

@@ -155,7 +155,6 @@ ERROR HY000: Table 't2' was locked with a READ lock and can't be updated
 UPDATE t1,t2 SET t1.d=t2.d,t2.d=30 WHERE t1.n=t2.n;
 ERROR HY000: Table 't2' was locked with a READ lock and can't be updated
 UPDATE t1,t2 SET t1.d=t2.d WHERE t1.n=t2.n;
-ERROR HY000: Table 't2' was locked with a READ lock and can't be updated
 unlock tables;
 LOCK TABLES t1 write, t2 write;
 UPDATE t1,t2 SET t1.d=t2.d WHERE t1.n=t2.n;
@@ -461,6 +460,7 @@ drop table t1, t2, t3;
 create table t1 (col1 int);
 create table t2 (col1 int);
 update t1,t2 set t1.col1 = (select max(col1) from t1) where t1.col1 = t2.col1;
+ERROR HY000: You can't specify target table 't1' for update in FROM clause
 delete t1 from t1,t2 where t1.col1 < (select max(col1) from t1) and t1.col1 = t2.col1;
 ERROR HY000: You can't specify target table 't1' for update in FROM clause
 drop table t1,t2;

mysql-test/r/view.result

@@ -1339,16 +1339,14 @@ c
 prepare stmt1 from "update v1,t1 set v1.s1=? where t1.s1=v1.s1";
 set @arg='d';
 execute stmt1 using @arg;
-ERROR HY000: Table 't1' is read only
 select * from v1;
 s1
-c
+d
 set @arg='e';
 execute stmt1 using @arg;
-ERROR HY000: Table 't1' is read only
 select * from v1;
 s1
-c
+e
 deallocate prepare stmt1;
 drop view v1;
 drop table t1;

mysql-test/t/multi_update.test

@@ -159,8 +159,6 @@ LOCK TABLES t1 write, t2 read;
 DELETE t1.*, t2.* FROM t1,t2 where t1.n=t2.n;
 --error 1099
 UPDATE t1,t2 SET t1.d=t2.d,t2.d=30 WHERE t1.n=t2.n;
---QQ This should not generate an error
---error 1099
 UPDATE t1,t2 SET t1.d=t2.d WHERE t1.n=t2.n;
 unlock tables;
 LOCK TABLES t1 write, t2 write;
@@ -428,7 +426,7 @@ drop table t1, t2, t3;
 #
 create table t1 (col1 int); 
 create table t2 (col1 int);
--- QQ The following should give error 1093
+-- error 1093
 update t1,t2 set t1.col1 = (select max(col1) from t1) where t1.col1 = t2.col1;
 -- error 1093
 delete t1 from t1,t2 where t1.col1 < (select max(col1) from t1) and t1.col1 = t2.col1;

mysql-test/t/view.test

@@ -1300,13 +1300,9 @@ update v1,t1 set v1.s1='c' where t1.s1=v1.s1;
 select * from v1;
 prepare stmt1 from "update v1,t1 set v1.s1=? where t1.s1=v1.s1";
 set @arg='d';
--- QQ This should not generate an error
---error 1036
 execute stmt1 using @arg;
 select * from v1;
 set @arg='e';
--- QQ This should not generate an error
---error 1036
 execute stmt1 using @arg;
 select * from v1;
 deallocate prepare stmt1;

sql/mysql_priv.h

@@ -565,7 +565,11 @@ int mysql_explain_select(THD *thd, SELECT_LEX *sl, char const *type,
 			 select_result *result);
 int mysql_union(THD *thd, LEX *lex, select_result *result,
 		SELECT_LEX_UNIT *unit);
-int mysql_handle_derived(LEX *lex);
+int mysql_handle_derived(LEX *lex, int (*processor)(THD *thd,
+                                                    st_lex *lex,
+                                                    st_table_list *table));
+int mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *t);
+int mysql_derived_filling(THD *thd, LEX *lex, TABLE_LIST *t);
 Field *create_tmp_field(THD *thd, TABLE *table,Item *item, Item::Type type,
 			Item ***copy_func, Field **from_field,
 			bool group, bool modify_item, uint convert_blob_length);
@@ -792,7 +796,6 @@ void wait_for_refresh(THD *thd);
 int open_tables(THD *thd, TABLE_LIST *tables, uint *counter);
 int simple_open_n_lock_tables(THD *thd,TABLE_LIST *tables);
 int open_and_lock_tables(THD *thd,TABLE_LIST *tables);
-void relink_tables_for_derived(THD *thd);
 int lock_tables(THD *thd, TABLE_LIST *tables, uint counter);
 TABLE *open_temporary_table(THD *thd, const char *path, const char *db,
 			    const char *table_name, bool link_in_list);

sql/sql_base.cc

@@ -44,6 +44,7 @@ static my_bool open_new_frm(const char *path, const char *alias,
 			    uint db_stat, uint prgflag,
 			    uint ha_open_flags, TABLE *outparam,
 			    TABLE_LIST *table_desc, MEM_ROOT *mem_root);
+static void relink_tables_for_multidelete(THD *thd);
 
 extern "C" byte *table_cache_key(const byte *record,uint *length,
 				 my_bool not_used __attribute__((unused)))
@@ -1859,19 +1860,21 @@ int open_and_lock_tables(THD *thd, TABLE_LIST *tables)
   uint counter;
   if (open_tables(thd, tables, &counter) ||
       lock_tables(thd, tables, counter) ||
-      mysql_handle_derived(thd->lex))
+      mysql_handle_derived(thd->lex, &mysql_derived_prepare) ||
+      (thd->fill_derived_tables() &&
+       mysql_handle_derived(thd->lex, &mysql_derived_filling)))
     DBUG_RETURN(thd->net.report_error ? -1 : 1); /* purecov: inspected */
-  relink_tables_for_derived(thd);
+  relink_tables_for_multidelete(thd);
   DBUG_RETURN(0);
 }
 
 
 /*
   Let us propagate pointers to open tables from global table list
-  to table lists in particular selects if needed.
+  to table lists for multi-delete
 */
 
-void relink_tables_for_derived(THD *thd)
+static void relink_tables_for_multidelete(THD *thd)
 {
   if (thd->lex->all_selects_list->next_select_in_list() ||
       thd->lex->time_zone_tables_used)

sql/sql_class.h

@@ -1131,6 +1131,10 @@ public:
   {
     return command == COM_PREPARE;
   }
+  inline bool fill_derived_tables()
+  {
+    return !only_prepare() && !lex->only_view_structure();
+  }
   inline gptr trans_alloc(unsigned int size)
   {
     return alloc_root(&transaction.mem_root,size);

sql/sql_derived.cc

@@ -25,15 +25,15 @@
 #include "sql_select.h"
 #include "sql_acl.h"
 
-static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *s,
-			 TABLE_LIST *t);
+
 
 /*
-  Resolve derived tables in all queries
+  call given derived table processor (preparing or filling tables)
 
   SYNOPSIS
     mysql_handle_derived()
     lex                 LEX for this thread
+    processor           procedure of derived table processing
 
   RETURN
     0	ok
@@ -42,7 +42,7 @@ static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *s,
 */
 
 int
-mysql_handle_derived(LEX *lex)
+mysql_handle_derived(LEX *lex, int (*processor)(THD*, LEX*, TABLE_LIST*))
 {
   if (lex->derived_tables)
   {
@@ -55,15 +55,9 @@ mysql_handle_derived(LEX *lex)
 	   cursor= cursor->next_local)
       {
 	int res;
-	if (cursor->derived && (res= mysql_derived(lex->thd, lex,
-						   cursor->derived,
-						   cursor)))
-	{
+	if ((res= (*processor)(lex->thd, lex, cursor)))
 	  return res;
       }
-	else if (cursor->ancestor)
-	  cursor->set_ancestor();
-      }
       if (lex->describe)
       {
 	/*
@@ -80,20 +74,16 @@ mysql_handle_derived(LEX *lex)
 
 
 /*
-  Resolve derived tables in all queries
+  Create temporary table structure (but do not fill it)
 
   SYNOPSIS
     mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit, TABLE_LIST *t)
     thd			Thread handle
     lex                 LEX for this thread
-    unit                node that contains all SELECT's for derived tables
-    t                   TABLE_LIST for the upper SELECT
+    orig_table_list     TABLE_LIST for the upper SELECT
 
   IMPLEMENTATION
-    Derived table is resolved with temporary table. It is created based on the
-    queries defined. After temporary table is created, if this is not EXPLAIN,
-    then the entire unit / node is deleted. unit is deleted if UNION is used 
-    for derived table and node is deleted is it is a  simple SELECT.
+    Derived table is resolved with temporary table.
 
     After table creation, the above TABLE_LIST is updated with a new table.
 
@@ -107,19 +97,19 @@ mysql_handle_derived(LEX *lex)
     0	ok
     1	Error
     -1	Error and error message given
-*/  
-
+  */
 
-static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit,
-			 TABLE_LIST *org_table_list)
+int mysql_derived_prepare(THD *thd, LEX *lex, TABLE_LIST *orig_table_list)
 {
+  SELECT_LEX_UNIT *unit= orig_table_list->derived;
+  int res= 0;
+  if (unit)
+  {
     SELECT_LEX *first_select= unit->first_select();
-  TABLE *table;
-  int res;
+    TABLE *table= 0;
     select_union *derived_result;
     bool is_union= first_select->next_select() && 
       first_select->next_select()->linkage == UNION_TYPE;
-  SELECT_LEX *save_current_select= lex->current_select;
     DBUG_ENTER("mysql_derived");
 
     if (!(derived_result= new select_union(0)))
@@ -142,24 +132,90 @@ static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit,
 				  (first_select->options | thd->options |
 				   TMP_TABLE_ALL_COLUMNS),
 				  HA_POS_ERROR,
-				org_table_list->alias)))
+				  orig_table_list->alias)))
     {
       res= -1;
       goto exit;
     }
     derived_result->set_table(table);
 
+exit:
     /*
       if it is preparation PS only or commands that need only VIEW structure
       then we do not need real data and we can skip execution (and parameters
       is not defined, too)
     */
-  if (!thd->only_prepare() && !lex->only_view_structure())
+    if (res)
     {
+      if (table)
+	free_tmp_table(thd, table);
+      delete derived_result;
+    }
+    else
+    {
+      if (!thd->fill_derived_tables())
+	delete derived_result;
+      orig_table_list->derived_result= derived_result;
+      orig_table_list->table= table;
+      orig_table_list->real_name= table->real_name;
+      table->derived_select_number= first_select->select_number;
+      table->tmp_table= TMP_TABLE;
+#ifndef NO_EMBEDDED_ACCESS_CHECKS
+      table->grant.privilege= SELECT_ACL;
+#endif
+      orig_table_list->db= (char *)"";
+      // Force read of table stats in the optimizer
+      table->file->info(HA_STATUS_VARIABLE);
+      /* Add new temporary table to list of open derived tables */
+      table->next= thd->derived_tables;
+      thd->derived_tables= table;
+    }
+  }
+  else if (orig_table_list->ancestor)
+    orig_table_list->set_ancestor();
+  return (res);
+}
+
+
+/*
+  fill derived table
+
+  SYNOPSIS
+    mysql_derived_filling()
+    thd			Thread handle
+    lex                 LEX for this thread
+    unit                node that contains all SELECT's for derived tables
+    orig_table_list     TABLE_LIST for the upper SELECT
+
+  IMPLEMENTATION
+    Derived table is resolved with temporary table. It is created based on the
+    queries defined. After temporary table is filled, if this is not EXPLAIN,
+    then the entire unit / node is deleted. unit is deleted if UNION is used
+    for derived table and node is deleted is it is a  simple SELECT.
+
+  RETURN
+    0	ok
+    1	Error
+    -1	Error and error message given
+  */
+
+int mysql_derived_filling(THD *thd, LEX *lex, TABLE_LIST *orig_table_list)
+{
+  TABLE *table= orig_table_list->table;
+  SELECT_LEX_UNIT *unit= orig_table_list->derived;
+  int res= 0;
+
+  /*check that table creation pass without problem and it is derived table */
+  if (table && unit)
+  {
+    SELECT_LEX *first_select= unit->first_select();
+    select_union *derived_result= orig_table_list->derived_result;
+    SELECT_LEX *save_current_select= lex->current_select;
+    bool is_union= first_select->next_select() &&
+      first_select->next_select()->linkage == UNION_TYPE;
     if (is_union)
     {
       // execute union without clean up
-      if (!(res= unit->prepare(thd, derived_result, SELECT_NO_UNLOCK)))
       res= unit->exec();
     }
     else
@@ -186,7 +242,6 @@ static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit,
 			 SELECT_NO_UNLOCK),
 			derived_result, unit, first_select);
     }
-  }
 
     if (!res)
     {
@@ -196,39 +251,18 @@ static int mysql_derived(THD *thd, LEX *lex, SELECT_LEX_UNIT *unit,
       */
       if (derived_result->flush())
         res= 1;
-    else
-    {
-      org_table_list->real_name= table->real_name;
-      org_table_list->table= table;
-      table->derived_select_number= first_select->select_number;
-      table->tmp_table= TMP_TABLE;
-#ifndef NO_EMBEDDED_ACCESS_CHECKS
-      table->grant.privilege= SELECT_ACL;
-#endif
-      org_table_list->db= (char *)"";
-      // Force read of table stats in the optimizer
-      table->file->info(HA_STATUS_VARIABLE);
-    }
 
       if (!lex->describe)
         unit->cleanup();
-    if (res)
-      free_tmp_table(thd, table);
-    else
-    {
-      /* Add new temporary table to list of open derived tables */
-      table->next= thd->derived_tables;
-      thd->derived_tables= table;
-    }
     }
     else
     {
       free_tmp_table(thd, table);
       unit->cleanup();
     }
-
-exit:
-  delete derived_result;
     lex->current_select= save_current_select;
-  DBUG_RETURN(res);
+    if (res)
+      free_tmp_table(thd, table);
+  }
+  return res;
 }

sql/sql_lex.cc

@@ -176,6 +176,7 @@ void lex_start(THD *thd, uchar *buf,uint length)
   lex->sphead= NULL;
   lex->spcont= NULL;
   lex->trg_table= NULL;
+  lex->proc_list.first= 0;
 
   extern byte *sp_lex_spfuns_key(const byte *ptr, uint *plen, my_bool first);
   hash_free(&lex->spfuns);

sql/sql_load.cc

@@ -91,7 +91,7 @@ int mysql_load(THD *thd,sql_exchange *ex,TABLE_LIST *table_list,
   int error;
   String *field_term=ex->field_term,*escaped=ex->escaped;
   String *enclosed=ex->enclosed;
-  Item *unused_conds;
+  Item *unused_conds= 0;
   bool is_fifo=0;
 #ifndef EMBEDDED_LIBRARY
   LOAD_FILE_INFO lf_info;

sql/sql_parse.cc

@@ -4472,7 +4472,6 @@ mysql_init_select(LEX *lex)
   {
     DBUG_ASSERT(lex->result == 0);
     lex->exchange= 0;
-    lex->proc_list.first= 0;
   }
 }
 

sql/sql_prepare.cc

@@ -1314,7 +1314,11 @@ static int mysql_test_multiupdate(Prepared_statement *stmt,
   int res;
   if ((res= multi_update_precheck(stmt->thd, tables)))
     return res;
-  return select_like_statement_test(stmt, tables, &mysql_multi_update_prepare);
+  /*
+    here we do not pass tables for opening, tables will be opened and locked
+    by mysql_multi_update_prepare
+  */
+  return select_like_statement_test(stmt, 0, &mysql_multi_update_prepare);
 }
 
 

sql/sql_update.cc

@@ -578,10 +578,17 @@ int mysql_multi_update_prepare(THD *thd)
   TABLE_LIST *table_list= lex->query_tables;
   List<Item> *fields= &lex->select_lex.item_list;
   TABLE_LIST *tl;
-  table_map tables_for_update= 0, readonly_tables= 0;
+  table_map tables_for_update;
   int res;
   bool update_view= 0;
+  uint  table_count;
+  const bool using_lock_tables= thd->locked_tables != 0;
   DBUG_ENTER("mysql_multi_update_prepare");
+
+  /* open tables and create derived ones, but do not lock and fill them */
+  if (open_tables(thd, table_list, & table_count) ||
+      mysql_handle_derived(lex, &mysql_derived_prepare))
+    DBUG_RETURN(thd->net.report_error ? -1 : 1);
   /*
     Ensure that we have update privilege for all tables and columns in the
     SET part
@@ -606,9 +613,9 @@ int mysql_multi_update_prepare(THD *thd)
     call in setup_tables()).
   */
   if (setup_tables(thd, table_list, &lex->select_lex.where) ||
-      (thd->lex->select_lex.no_wrap_view_item= 1,
+      (lex->select_lex.no_wrap_view_item= 1,
        res= setup_fields(thd, 0, table_list, *fields, 1, 0, 0),
-       thd->lex->select_lex.no_wrap_view_item= 0,
+       lex->select_lex.no_wrap_view_item= 0,
        res))
     DBUG_RETURN(-1);
 
@@ -626,18 +633,10 @@ int mysql_multi_update_prepare(THD *thd)
     DBUG_RETURN(-1);
   }
 
-  {
-    // Find tables used in items
-    List_iterator_fast<Item> it(*fields);
-    Item *item;
-    while ((item= it++))
-    {
-      tables_for_update|= item->used_tables();
-    }
-  }
+  tables_for_update= get_table_map(fields);
 
   /*
-    Count tables and setup timestamp handling
+    Setup timestamp handling and locking mode
   */
   for (tl= table_list; tl ; tl= tl->next_local)
   {
@@ -651,22 +650,43 @@ int mysql_multi_update_prepare(THD *thd)
         table->timestamp_field->query_id == thd->query_id)
       table->timestamp_field_type= TIMESTAMP_NO_AUTO_SET;
 
-    if (!tl->updatable || check_key_in_view(thd, tl))
-      readonly_tables|= table->map;
-  }
-  if (tables_for_update & readonly_tables)
+    /* if table will be updated then check that it is unique */
+    if (table->map & tables_for_update)
     {
-    // find readonly table/view which cause error
-    for (tl= table_list; tl ; tl= tl->next_local)
-    {
-      if ((readonly_tables & tl->table->map) &&
-          (tables_for_update & tl->table->map))
+      if (!tl->updatable || check_key_in_view(thd, tl))
       {
         my_error(ER_NON_UPDATABLE_TABLE, MYF(0), tl->alias, "UPDATE");
         DBUG_RETURN(-1);
       }
+
+      /*
+        Multi-update can't be constructed over-union => we always have
+        single SELECT on top and have to check underlaying SELECTs of it
+      */
+      if (lex->select_lex.check_updateable_in_subqueries(tl->db,
+                                                         tl->real_name))
+      {
+        my_error(ER_UPDATE_TABLE_USED, MYF(0), tl->real_name);
+        DBUG_RETURN(-1);
       }
+      DBUG_PRINT("info",("setting table `%s` for update", tl->alias));
+      tl->lock_type= lex->multi_lock_option;
+      tl->updating= 1;
       }
+    else
+    {
+      DBUG_PRINT("info",("setting table `%s` for read-only", tl->alias));
+      tl->lock_type= TL_READ;
+      tl->updating= 0;
+    }
+    if (!using_lock_tables)
+      tl->table->reginfo.lock_type= tl->lock_type;
+  }
+  /* now lock and fill tables */
+  if (lock_tables(thd, table_list, table_count) ||
+      (thd->fill_derived_tables() &&
+       mysql_handle_derived(lex, &mysql_derived_filling)))
+    DBUG_RETURN(thd->net.report_error ? -1 : 1);
   DBUG_RETURN (0);
 }
 
@@ -688,11 +708,6 @@ int mysql_multi_update(THD *thd,
   multi_update *result;
   DBUG_ENTER("mysql_multi_update");
 
-  /* QQ: This should be fixed soon to get lower granularity locks */
-  select_lex->set_lock_for_tables(thd->lex->multi_lock_option);
-  if ((res= open_and_lock_tables(thd, table_list)))
-    DBUG_RETURN(res);
-
   if ((res= mysql_multi_update_prepare(thd)))
     DBUG_RETURN(res);
 

sql/table.h

@@ -222,6 +222,7 @@ struct st_table {
 #define VIEW_CHECK_SKIP       2
 
 struct st_lex;
+struct select_union;
 
 typedef struct st_table_list
 {
@@ -237,6 +238,11 @@ typedef struct st_table_list
   /* ... join ... USE INDEX ... IGNORE INDEX */
   List<String>	*use_index, *ignore_index;
   TABLE         *table;                 /* opened table */
+  /*
+    select_result for derived table to pass it from table creation to table
+    filling procedure
+  */
+  select_union  *derived_result;
   /*
     Reference from aux_tables to local list entry of main select of
     multi-delete statement: