Allow optimzation of multi-table-update also for InnoDB tables

MEMORY is alias for HEAP for CREATE TABLE ... TYPE=HEAP
Fixed bug in multi-table-update where a row could be updated several times


mysql-test/r/heap.result:
  Test of CREATE TABLE ... type=MEMORY
mysql-test/r/innodb.result:
  Added multi-update-test
mysql-test/r/multi_update.result:
  Added multi-update-test
mysql-test/t/heap.test:
  Test of CREATE TABLE ... type=MEMORY
mysql-test/t/innodb.test:
  Added multi-update-test
mysql-test/t/multi_update.test:
  Added multi-update-test
sql/ha_innodb.h:
  Allow optimzation of multi-table-update also for InnoDB tables
sql/handler.h:
  Allow optimzation of multi-update also for InnoDB tables
sql/key.cc:
  After merge fix
sql/lex.h:
  MEMORY is alias for HEAP
sql/sql_test.cc:
  Fixed wrong printf
sql/sql_update.cc:
  Fixed bug in multi-table-update where a row could be updated several times
sql/sql_yacc.yy:
  MEMORY is alias for HEAP

mysql-test/r/heap.result

@@ -23,7 +23,7 @@ a	b
 4	6
 alter table t1 add c int not null, add key (c,a);
 drop table t1;
-create table t1 (a int not null,b int not null, primary key (a)) type=heap comment="testing heaps";
+create table t1 (a int not null,b int not null, primary key (a)) type=memory comment="testing heaps";
 insert into t1 values(1,1),(2,2),(3,3),(4,4);
 delete from t1 where a > 0;
 select * from t1;

mysql-test/r/innodb.result

@@ -1122,3 +1122,82 @@ my-test-1	my-test-2
 COMMIT;
 set autocommit=1;
 DROP TABLE t1,t2,t3;
+CREATE TABLE t1 (a int not null primary key, b int not null, unique (b)) type=innodb;
+INSERT INTO t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+UPDATE t1 set a=a+100 where b between 2 and 3 and a < 1000;
+SELECT * from t1;
+a	b
+1	1
+102	2
+103	3
+4	4
+5	5
+6	6
+7	7
+8	8
+9	9
+drop table t1;
+CREATE TABLE t1 (a int not null primary key, b int not null, key (b)) type=innodb;
+CREATE TABLE t2 (a int not null primary key, b int not null, key (b)) type=innodb;
+INSERT INTO t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+INSERT INTO t2 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+update t1,t2 set t1.a=t1.a+100;
+select * from t1;
+a	b
+101	1
+102	2
+103	3
+104	4
+105	5
+106	6
+107	7
+108	8
+109	9
+update t1,t2 set t1.a=t1.a+100 where t1.a=101;
+select * from t1;
+a	b
+201	1
+102	2
+103	3
+104	4
+105	5
+106	6
+107	7
+108	8
+109	9
+update t1,t2 set t1.b=t1.b+10 where t1.b=2;
+select * from t1;
+a	b
+201	1
+103	3
+104	4
+105	5
+106	6
+107	7
+108	8
+109	9
+102	12
+update t1,t2 set t1.b=t1.b+2,t2.b=t1.b where t1.b between 3 and 5;
+select * from t1;
+a	b
+201	1
+103	5
+104	6
+106	6
+105	7
+107	7
+108	8
+109	9
+102	12
+select * from t2;
+a	b
+1	5
+2	5
+3	5
+4	5
+5	5
+6	5
+7	5
+8	5
+9	5
+drop table t1,t2;

mysql-test/r/multi_update.result

@@ -246,3 +246,67 @@ INSERT INTO t3 VALUES (1,'jedan'),(2,'dva');
 update t1,t2 set t1.naziv="aaaa" where t1.broj=t2.broj;
 update t1,t2,t3 set t1.naziv="bbbb", t2.naziv="aaaa" where t1.broj=t2.broj and t2.broj=t3.broj;
 drop table if exists t1,t2,t3;
+CREATE TABLE t1 (a int not null primary key, b int not null, key (b));
+CREATE TABLE t2 (a int not null primary key, b int not null, key (b));
+INSERT INTO t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+INSERT INTO t2 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+update t1,t2 set t1.a=t1.a+100;
+select * from t1;
+a	b
+101	1
+102	2
+103	3
+104	4
+105	5
+106	6
+107	7
+108	8
+109	9
+update t1,t2 set t1.a=t1.a+100 where t1.a=101;
+select * from t1;
+a	b
+201	1
+102	2
+103	3
+104	4
+105	5
+106	6
+107	7
+108	8
+109	9
+update t1,t2 set t1.b=t1.b+10 where t1.b=2;
+select * from t1;
+a	b
+201	1
+102	12
+103	3
+104	4
+105	5
+106	6
+107	7
+108	8
+109	9
+update t1,t2 set t1.b=t1.b+2,t2.b=t1.b where t1.b between 3 and 5;
+select * from t1;
+a	b
+201	1
+102	12
+103	5
+104	6
+105	7
+106	6
+107	7
+108	8
+109	9
+select * from t2;
+a	b
+1	3
+2	3
+3	3
+4	3
+5	3
+6	3
+7	3
+8	3
+9	3
+drop table t1,t2;

mysql-test/t/heap.test

@@ -17,7 +17,7 @@ select * from t1;
 alter table t1 add c int not null, add key (c,a);
 drop table t1;
 
-create table t1 (a int not null,b int not null, primary key (a)) type=heap comment="testing heaps";
+create table t1 (a int not null,b int not null, primary key (a)) type=memory comment="testing heaps";
 insert into t1 values(1,1),(2,2),(3,3),(4,4);
 delete from t1 where a > 0;
 select * from t1;

mysql-test/t/innodb.test

@@ -769,3 +769,31 @@ INSERT INTO t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
 UPDATE t1 set a=a+100 where b between 2 and 3 and a < 1000;
 SELECT * from t1;
 drop table t1;
+
+#
+# Test multi update with different join methods
+#
+
+CREATE TABLE t1 (a int not null primary key, b int not null, key (b)) type=innodb;
+CREATE TABLE t2 (a int not null primary key, b int not null, key (b)) type=innodb;
+INSERT INTO t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+INSERT INTO t2 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+
+# Full join, without key
+update t1,t2 set t1.a=t1.a+100;
+select * from t1;
+
+# unique key
+update t1,t2 set t1.a=t1.a+100 where t1.a=101;
+select * from t1;
+
+# ref key
+update t1,t2 set t1.b=t1.b+10 where t1.b=2;
+select * from t1;
+
+# Range key (in t1)
+update t1,t2 set t1.b=t1.b+2,t2.b=t1.b where t1.b between 3 and 5;
+select * from t1;
+select * from t2;
+
+drop table t1,t2;

mysql-test/t/multi_update.test

@@ -224,3 +224,31 @@ INSERT INTO t3 VALUES (1,'jedan'),(2,'dva');
 update t1,t2 set t1.naziv="aaaa" where t1.broj=t2.broj;
 update t1,t2,t3 set t1.naziv="bbbb", t2.naziv="aaaa" where t1.broj=t2.broj and t2.broj=t3.broj;
 drop table if exists t1,t2,t3;
+
+#
+# Test multi update with different join methods
+#
+
+CREATE TABLE t1 (a int not null primary key, b int not null, key (b));
+CREATE TABLE t2 (a int not null primary key, b int not null, key (b));
+INSERT INTO t1 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+INSERT INTO t2 values (1,1),(2,2),(3,3),(4,4),(5,5),(6,6),(7,7),(8,8),(9,9);
+
+# Full join, without key
+update t1,t2 set t1.a=t1.a+100;
+select * from t1;
+
+# unique key
+update t1,t2 set t1.a=t1.a+100 where t1.a=101;
+select * from t1;
+
+# ref key
+update t1,t2 set t1.b=t1.b+10 where t1.b=2;
+select * from t1;
+
+# Range key (in t1)
+update t1,t2 set t1.b=t1.b+2,t2.b=t1.b where t1.b between 3 and 5;
+select * from t1;
+select * from t2;
+
+drop table t1,t2;

sql/ha_innodb.h

@@ -82,8 +82,7 @@ class ha_innobase: public handler
 			  HA_PRIMARY_KEY_IN_READ_INDEX |
 			  HA_DROP_BEFORE_CREATE |
 			  HA_NO_PREFIX_CHAR_KEYS |
-			  HA_TABLE_SCAN_ON_INDEX | 
-			  HA_NOT_MULTI_UPDATE),
+			  HA_TABLE_SCAN_ON_INDEX),
 	  last_dup_key((uint) -1),
 	  start_of_scan(0)
   	{

sql/handler.h

@@ -67,7 +67,6 @@
 #define HA_CAN_FULLTEXT         (HA_NO_PREFIX_CHAR_KEYS*2)
 #define HA_CAN_SQL_HANDLER      (HA_CAN_FULLTEXT*2)
 #define HA_NO_AUTO_INCREMENT	(HA_CAN_SQL_HANDLER*2)
-#define HA_NOT_MULTI_UPDATE	(HA_NO_AUTO_INCREMENT*2)
 
 /*
   Next record gives next record according last record read (even

sql/key.cc

@@ -275,7 +275,7 @@ bool check_if_key_used(TABLE *table, uint idx, List<Item> &fields)
     key is not updated
   */
   if (idx != table->primary_key && table->primary_key < MAX_KEY &&
-      (table->file->option_flag() & HA_PRIMARY_KEY_IN_READ_INDEX))
+      (table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX))
     return check_if_key_used(table, table->primary_key, fields);
   return 0;
 }

sql/lex.h

@@ -240,6 +240,7 @@ static SYMBOL symbols[] = {
   { "MEDIUMINT",	SYM(MEDIUMINT),0,0},
   { "MERGE",		SYM(MERGE_SYM),0,0},
   { "MEDIUM",		SYM(MEDIUM_SYM),0,0},
+  { "MEMORY",		SYM(MEMORY_SYM),0,0},
   { "MIDDLEINT",	SYM(MEDIUMINT),0,0},	/* For powerbuilder */
   { "MIN_ROWS",		SYM(MIN_ROWS),0,0},
   { "MINUTE",		SYM(MINUTE_SYM),0,0},

sql/sql_test.cc

@@ -131,7 +131,7 @@ void TEST_filesort(SORT_FIELD *sortorder,uint s_length, ha_rows special)
   DBUG_LOCK_FILE;
   VOID(fputs("\nInfo about FILESORT\n",DBUG_FILE));
   if (special)
-    fprintf(DBUG_FILE,"Records to sort: %ld\n",special);
+    fprintf(DBUG_FILE,"Records to sort: %lu\n",(ulong) special);
   fprintf(DBUG_FILE,"Sortorder: %s\n",out.ptr());
   DBUG_UNLOCK_FILE;
   DBUG_VOID_RETURN;

sql/sql_update.cc

@@ -23,6 +23,8 @@
 #include "sql_acl.h"
 #include "sql_select.h"
 
+static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields);
+
 /* Return 0 if row hasn't changed */
 
 static bool compare_record(TABLE *table, ulong query_id)
@@ -520,11 +522,12 @@ int multi_update::prepare(List<Item> &not_used_values)
 
 
 /*
-  Store first used table in main_table as this should be updated first
-  This is because we know that no row in this table will be read twice.
+  Initialize table for multi table
 
-  Create temporary tables to store changed values for all other tables
-  that are updated.
+  IMPLEMENTATION
+    - Update first table in join on the fly, if possible
+    - Create temporary tables to store changed values for all other tables
+      that are updated (and main_table if the above doesn't hold).
 */
 
 bool
@@ -538,17 +541,25 @@ multi_update::initialize_tables(JOIN *join)
   main_table=join->join_tab->table;
   trans_safe= transactional_tables= main_table->file->has_transactions();
   log_delayed= trans_safe || main_table->tmp_table != NO_TMP_TABLE;
-  table_to_update= (main_table->file->table_flags() & HA_NOT_MULTI_UPDATE) ? 
-    (TABLE *) 0 : main_table;
-  /* Create a temporary table for all tables after except main table */
+  table_to_update= 0;
+
+  /* Create a temporary table for keys to all tables, except main table */
   for (table_ref= update_tables; table_ref; table_ref=table_ref->next)
   {
     TABLE *table=table_ref->table;
-    if (table != table_to_update)
-    {
     uint cnt= table_ref->shared;
-      ORDER     group;
     List<Item> temp_fields= *fields_for_table[cnt];
+    ORDER     group;
+
+    if (table == main_table)			// First table in join
+    {
+      if (safe_update_on_fly(join->join_tab, &temp_fields))
+      {
+	table_to_update= main_table;		// Update table on the fly
+	continue;
+      }
+    }
+
     TMP_TABLE_PARAM *tmp_param= tmp_table_param+cnt;
 
     /*
@@ -580,10 +591,63 @@ multi_update::initialize_tables(JOIN *join)
       DBUG_RETURN(1);
     tmp_tables[cnt]->file->extra(HA_EXTRA_WRITE_CACHE);
   }
-  }
   DBUG_RETURN(0);
 }
 
+/*
+  Check if table is safe to update on fly
+
+  SYNOPSIS
+    safe_update_on_fly
+    join_tab		How table is used in join
+    fields		Fields that are updated
+
+  NOTES
+    We can update the first table in join on the fly if we know that
+    a row in this tabel will never be read twice. This is true under
+    the folloing conditions:
+
+    - We are doing a table scan and the data is in a separate file (MyISAM) or
+      if we don't update a clustered key.
+
+    - We are doing a range scan and we don't update the scan key or
+      the primary key for a clustered table handler.
+
+  WARNING
+    This code is a bit dependent of how make_join_readinfo() works.
+
+  RETURN
+    0		Not safe to update
+    1		Safe to update
+*/
+
+static bool safe_update_on_fly(JOIN_TAB *join_tab, List<Item> *fields)
+{
+  TABLE *table= join_tab->table;
+  switch (join_tab->type) {
+  case JT_SYSTEM:
+  case JT_CONST:
+  case JT_EQ_REF:
+    return 1;					// At most one matching row
+  case JT_REF:
+    return !check_if_key_used(table, join_tab->ref.key, *fields);
+  case JT_ALL:
+    /* If range search on index */
+    if (join_tab->quick)
+      return !check_if_key_used(table, join_tab->quick->index,
+				*fields);
+    /* If scanning in clustered key */
+    if ((table->file->table_flags() & HA_PRIMARY_KEY_IN_READ_INDEX) &&
+	table->primary_key < MAX_KEY)
+      return !check_if_key_used(table, table->primary_key, *fields);
+    return 1;
+  default:
+    break;					// Avoid compler warning
+  }
+  return 0;
+}
+
+
 
 multi_update::~multi_update()
 {

sql/sql_yacc.yy

@@ -256,6 +256,7 @@ bool my_yyoverflow(short **a, YYSTYPE **b,int *yystacksize);
 %token	MAX_UPDATES_PER_HOUR
 %token	MEDIUM_SYM
 %token	MERGE_SYM
+%token	MEMORY_SYM
 %token	MIN_ROWS
 %token	MYISAM_SYM
 %token	NATIONAL_SYM
@@ -871,6 +872,7 @@ table_types:
 	| MYISAM_SYM	{ $$= DB_TYPE_MYISAM; }
 	| MERGE_SYM	{ $$= DB_TYPE_MRG_MYISAM; }
 	| HEAP_SYM	{ $$= DB_TYPE_HEAP; }
+	| MEMORY_SYM	{ $$= DB_TYPE_HEAP; }
 	| BERKELEY_DB_SYM { $$= DB_TYPE_BERKELEY_DB; }
 	| INNOBASE_SYM  { $$= DB_TYPE_INNODB; };
 
@@ -3316,6 +3318,7 @@ keyword:
 	| MAX_UPDATES_PER_HOUR  {}
 	| MEDIUM_SYM		{}
 	| MERGE_SYM		{}
+	| MEMORY_SYM		{}
 	| MINUTE_SYM		{}
 	| MIN_ROWS		{}
 	| MODIFY_SYM		{}