Don't automaticly generate a new key for a foreign key constraint if there is already a usable key.

Prefer not automatic keys before automatic keys. If there is two conf

.bzrignore

@@ -774,3 +774,8 @@ ndb/lib/libndbclient.so
 ndb/lib/libndbclient_extra.so
 libmysqld/discover.cc
 include/readline
+ndb/config/autom4te.cache/*
+ndb/config/config.mk
+ndb/src/common/mgmcommon/printConfig/*.d
+ndb/src/mgmclient/test_cpcd/*.d
+*.d

include/my_base.h

@@ -191,7 +191,7 @@ enum ha_base_keytype {
 #define HA_UNIQUE_CHECK		256	/* Check the key for uniqueness */
 #define HA_SPATIAL		1024    /* For spatial search */
 #define HA_NULL_ARE_EQUAL	2048	/* NULL in key are cmp as equal */
-
+#define HA_GENERATED_KEY	8192	/* Automaticly generated key */
 
 	/* Automatic bits in key-flag */
 

mysql-test/r/constraints.result

@@ -22,6 +22,8 @@ show create table t1;
 Table	Create Table
 t1	CREATE TABLE `t1` (
   `a` int(11) default NULL,
-  UNIQUE KEY `constraint_1` (`a`)
+  UNIQUE KEY `constraint_1` (`a`),
+  UNIQUE KEY `key_1` (`a`),
+  UNIQUE KEY `key_2` (`a`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;

mysql-test/r/create.result

@@ -155,7 +155,37 @@ t1	CREATE TABLE `t1` (
   `a` int(11) NOT NULL default '0',
   `b` int(11) default NULL,
   PRIMARY KEY  (`a`),
-  KEY `b` (`b`)
+  KEY `b` (`b`),
+  KEY `b_2` (`b`),
+  KEY `b_3` (`b`),
+  KEY `b_4` (`b`),
+  KEY `b_5` (`b`),
+  KEY `b_6` (`b`),
+  KEY `b_7` (`b`),
+  KEY `b_8` (`b`),
+  KEY `b_9` (`b`),
+  KEY `b_10` (`b`),
+  KEY `b_11` (`b`),
+  KEY `b_12` (`b`),
+  KEY `b_13` (`b`),
+  KEY `b_14` (`b`),
+  KEY `b_15` (`b`),
+  KEY `b_16` (`b`),
+  KEY `b_17` (`b`),
+  KEY `b_18` (`b`),
+  KEY `b_19` (`b`),
+  KEY `b_20` (`b`),
+  KEY `b_21` (`b`),
+  KEY `b_22` (`b`),
+  KEY `b_23` (`b`),
+  KEY `b_24` (`b`),
+  KEY `b_25` (`b`),
+  KEY `b_26` (`b`),
+  KEY `b_27` (`b`),
+  KEY `b_28` (`b`),
+  KEY `b_29` (`b`),
+  KEY `b_30` (`b`),
+  KEY `b_31` (`b`)
 ) ENGINE=MyISAM DEFAULT CHARSET=latin1
 drop table t1;
 create table t1 select if(1,'1','0'), month("2002-08-02");

mysql-test/r/innodb.result

@@ -371,6 +371,7 @@ t1	0	PRIMARY	2	b	A	#	NULL	NULL		BTREE
 t1	0	c	1	c	A	#	NULL	NULL		BTREE	
 t1	0	b	1	b	A	#	NULL	NULL		BTREE	
 t1	1	a	1	a	A	#	NULL	NULL		BTREE	
+t1	1	a_2	1	a	A	#	NULL	NULL		BTREE	
 drop table t1;
 create table t1 (col1 int not null, col2 char(4) not null, primary key(col1));
 alter table t1 engine=innodb;
@@ -1442,3 +1443,101 @@ drop table t1;
 create table t1 (a int) engine=innodb;
 create table t2 like t1;
 drop table t1,t2;
+create table t1 (id int(11) not null, id2 int(11) not null, unique (id,id2)) engine=innodb;
+create table t2 (id int(11) not null, constraint t1_id_fk foreign key ( id ) references t1 (id)) engine = innodb;
+show create table t1;
+Table	Create Table
+t1	CREATE TABLE `t1` (
+  `id` int(11) NOT NULL default '0',
+  `id2` int(11) NOT NULL default '0',
+  UNIQUE KEY `id` (`id`,`id2`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  KEY `t1_id_fk` (`id`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+create index id on t2 (id);
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  KEY `id` (`id`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+create index id2 on t2 (id);
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  KEY `id` (`id`),
+  KEY `id2` (`id`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop index id2 on t2;
+drop index id on t2;
+Got one of the listed errors
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  KEY `id` (`id`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table t2;
+create table t2 (id int(11) not null, id2 int(11) not null, constraint t1_id_fk foreign key (id,id2) references t1 (id,id2)) engine = innodb;
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  `id2` int(11) NOT NULL default '0',
+  KEY `t1_id_fk` (`id`,`id2`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`, `id2`) REFERENCES `t1` (`id`, `id2`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+create unique index id on t2 (id,id2);
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  `id2` int(11) NOT NULL default '0',
+  UNIQUE KEY `id` (`id`,`id2`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`, `id2`) REFERENCES `t1` (`id`, `id2`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table t2;
+create table t2 (id int(11) not null, id2 int(11) not null, unique (id,id2),constraint t1_id_fk foreign key (id2,id) references t1 (id,id2)) engine = innodb;
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  `id2` int(11) NOT NULL default '0',
+  UNIQUE KEY `id` (`id`,`id2`),
+  KEY `t1_id_fk` (`id2`,`id`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id2`, `id`) REFERENCES `t1` (`id`, `id2`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table t2;
+create table t2 (id int(11) not null, id2 int(11) not null, unique (id,id2), constraint t1_id_fk foreign key (id) references t1 (id)) engine = innodb;
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  `id2` int(11) NOT NULL default '0',
+  UNIQUE KEY `id` (`id`,`id2`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id`) REFERENCES `t1` (`id`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table t2;
+create table t2 (id int(11) not null, id2 int(11) not null, unique (id,id2),constraint t1_id_fk foreign key (id2,id) references t1 (id,id2)) engine = innodb;
+show create table t2;
+Table	Create Table
+t2	CREATE TABLE `t2` (
+  `id` int(11) NOT NULL default '0',
+  `id2` int(11) NOT NULL default '0',
+  UNIQUE KEY `id` (`id`,`id2`),
+  KEY `t1_id_fk` (`id2`,`id`),
+  CONSTRAINT `t1_id_fk` FOREIGN KEY (`id2`, `id`) REFERENCES `t1` (`id`, `id2`)
+) ENGINE=InnoDB DEFAULT CHARSET=latin1
+drop table t2;
+create table t2 (id int(11) not null, id2 int(11) not null, constraint t1_id_fk foreign key (id2,id) references t1 (id)) engine = innodb;
+ERROR HY000: Can't create table './test/t2.frm' (errno: 150)
+drop table t1;

mysql-test/t/innodb.test

@@ -1044,3 +1044,46 @@ drop table t1;
 create table t1 (a int) engine=innodb;
 create table t2 like t1;
 drop table t1,t2;
+
+#
+# Test of automaticly created foreign keys
+#
+
+create table t1 (id int(11) not null, id2 int(11) not null, unique (id,id2)) engine=innodb;
+create table t2 (id int(11) not null, constraint t1_id_fk foreign key ( id ) references t1 (id)) engine = innodb;
+show create table t1;
+show create table t2;
+create index id on t2 (id);
+show create table t2;
+create index id2 on t2 (id);
+show create table t2;
+drop index id2 on t2;
+--error 1025,1025
+drop index id on t2;
+show create table t2;
+drop table t2;
+
+create table t2 (id int(11) not null, id2 int(11) not null, constraint t1_id_fk foreign key (id,id2) references t1 (id,id2)) engine = innodb;
+show create table t2;
+create unique index id on t2 (id,id2);
+show create table t2;
+drop table t2;
+
+# Check foreign key columns created in different order than key columns
+create table t2 (id int(11) not null, id2 int(11) not null, unique (id,id2),constraint t1_id_fk foreign key (id2,id) references t1 (id,id2)) engine = innodb;
+show create table t2;
+drop table t2;
+
+create table t2 (id int(11) not null, id2 int(11) not null, unique (id,id2), constraint t1_id_fk foreign key (id) references t1 (id)) engine = innodb;
+show create table t2;
+drop table t2;
+
+create table t2 (id int(11) not null, id2 int(11) not null, unique (id,id2),constraint t1_id_fk foreign key (id2,id) references t1 (id,id2)) engine = innodb;
+show create table t2;
+drop table t2;
+
+# Test error handling
+--error 1005
+create table t2 (id int(11) not null, id2 int(11) not null, constraint t1_id_fk foreign key (id2,id) references t1 (id)) engine = innodb;
+
+drop table t1;

mysql-test/t/key_cache.test

@@ -71,7 +71,7 @@ show status like 'key_blocks_used';
 # Following results differs on 64 and 32 bit systems because of different
 # pointer sizes, which takes up different amount of space in key cache
 
---replace_result 1812 KEY_BLOCKS_UNUSED 1793 KEY_BLOCKS_UNUSED
+--replace_result 1812 KEY_BLOCKS_UNUSED 1793 KEY_BLOCKS_UNUSED 1674 KEY_BLOCKS_UNUSED 1818 KEY_BLOCKS_UNUSED
 show status like 'key_blocks_unused';
 
 insert into t1 values (1, 'qqqq'), (11, 'yyyy');
@@ -84,7 +84,7 @@ update t1 set p=2 where p=1;
 update t2 set i=2 where i=1;
 
 show status like 'key_blocks_used';
---replace_result 1808 KEY_BLOCKS_UNUSED 1789 KEY_BLOCKS_UNUSED
+--replace_result 1808 KEY_BLOCKS_UNUSED 1789 KEY_BLOCKS_UNUSED 1670 KEY_BLOCKS_UNUSED 1814 KEY_BLOCKS_UNUSED
 show status like 'key_blocks_unused';
 
 cache index t1 key (`primary`) in keycache1;
@@ -146,7 +146,7 @@ cache index t1,t2 in default;
 drop table t1,t2,t3;
 
 show status like 'key_blocks_used';
---replace_result 1812 KEY_BLOCKS_UNUSED 1793 KEY_BLOCKS_UNUSED
+--replace_result 1812 KEY_BLOCKS_UNUSED 1793 KEY_BLOCKS_UNUSED 1674 KEY_BLOCKS_UNUSED 1818 KEY_BLOCKS_UNUSED
 show status like 'key_blocks_unused';
 
 # Cleanup

sql/sql_acl.cc

@@ -1918,7 +1918,8 @@ static int replace_column_table(GRANT_TABLE *g_t,
     ulong privileges = xx->rights;
     bool old_row_exists=0;
     key_restore(table,key,0,key_length);
-    table->field[4]->store(xx->column.ptr(),xx->column.length(),&my_charset_latin1);
+    table->field[4]->store(xx->column.ptr(),xx->column.length(),
+                           &my_charset_latin1);
 
     if (table->file->index_read(table->record[0],(byte*) table->field[0]->ptr,
 				0, HA_READ_KEY_EXACT))
@@ -1931,9 +1932,10 @@ static int replace_column_table(GRANT_TABLE *g_t,
 	continue; /* purecov: inspected */
       }
       old_row_exists = 0;
-      restore_record(table,default_values);				// Get empty record
+      restore_record(table,default_values);		// Get empty record
       key_restore(table,key,0,key_length);
-      table->field[4]->store(xx->column.ptr(),xx->column.length(), &my_charset_latin1);
+      table->field[4]->store(xx->column.ptr(),xx->column.length(),
+                             &my_charset_latin1);
     }
     else
     {

sql/sql_class.cc

@@ -84,26 +84,71 @@ bool key_part_spec::operator==(const key_part_spec& other) const
   return length == other.length && !strcmp(field_name, other.field_name);
 }
 
-/* Equality comparison of keys (ignoring name) */
-bool Key::operator==(Key& other)
+
+/*
+  Test if a foreign key is a prefix of the given key
+  (ignoring key name, key type and order of columns)
+
+  NOTES:
+    This is only used to test if an index for a FOREIGN KEY exists
+
+  IMPLEMENTATION
+    We only compare field names
+
+  RETURN
+    0	Generated key is a prefix of other key
+    1	Not equal
+*/
+
+bool foreign_key_prefix(Key *a, Key *b)
 {
-  if (type == other.type &&
-      algorithm == other.algorithm &&
-      columns.elements == other.columns.elements)
+  /* Ensure that 'a' is the generated key */
+  if (a->generated)
+  {
+    if (b->generated && a->columns.elements > b->columns.elements)
+      swap(Key*, a, b);                          // Put shorter key in 'a'
+  }
+  else
   {
-    List_iterator<key_part_spec> col_it1(columns);
-    List_iterator<key_part_spec> col_it2(other.columns);
-    const key_part_spec *col1, *col2;
-    while ((col1 = col_it1++))
+    if (!b->generated)
+      return TRUE;                              // No foreign key
+    swap(Key*, a, b);                           // Put generated key in 'a'
+  }
+
+  /* Test if 'a' is a prefix of 'b' */
+  if (a->columns.elements > b->columns.elements)
+    return TRUE;                                // Can't be prefix
+
+  List_iterator<key_part_spec> col_it1(a->columns);
+  List_iterator<key_part_spec> col_it2(b->columns);
+  const key_part_spec *col1, *col2;
+
+#ifdef ENABLE_WHEN_INNODB_CAN_HANDLE_SWAPED_FOREIGN_KEY_COLUMNS
+  while ((col1= col_it1++))
+  {
+    bool found= 0;
+    col_it2.rewind();
+    while ((col2= col_it2++))
     {
-      col2 = col_it2++;
-      DBUG_ASSERT(col2 != NULL);
-      if (!(*col1 == *col2))
-	return false;
+      if (*col1 == *col2)
+      {
+        found= TRUE;
+	break;
+      }
     }
-    return true;
+    if (!found)
+      return TRUE;                              // Error
+  }
+  return FALSE;                                 // Is prefix
+#else
+  while ((col1= col_it1++))
+  {
+    col2= col_it2++;
+    if (!(*col1 == *col2))
+      return TRUE;
   }
-  return false;
+  return FALSE;                                 // Is prefix
+#endif
 }
 
 

sql/sql_class.h

@@ -240,14 +240,16 @@ public:
   enum ha_key_alg algorithm;
   List<key_part_spec> columns;
   const char *name;
+  bool generated;
 
   Key(enum Keytype type_par, const char *name_arg, enum ha_key_alg alg_par,
-      List<key_part_spec> &cols)
-    :type(type_par), algorithm(alg_par), columns(cols), name(name_arg)
+      bool generated_arg, List<key_part_spec> &cols)
+    :type(type_par), algorithm(alg_par), columns(cols), name(name_arg),
+    generated(generated_arg)
   {}
   ~Key() {}
   /* Equality comparison of keys (ignoring name) */
-  bool operator==(Key& other);
+  friend bool foreign_key_prefix(Key *a, Key *b);
 };
 
 class Table_ident;
@@ -265,7 +267,7 @@ public:
   foreign_key(const char *name_arg, List<key_part_spec> &cols,
 	      Table_ident *table,   List<key_part_spec> &ref_cols,
 	      uint delete_opt_arg, uint update_opt_arg, uint match_opt_arg)
-    :Key(FOREIGN_KEY, name_arg, HA_KEY_ALG_UNDEF, cols),
+    :Key(FOREIGN_KEY, name_arg, HA_KEY_ALG_UNDEF, 0, cols),
     ref_table(table), ref_columns(cols),
     delete_opt(delete_opt_arg), update_opt(update_opt_arg),
     match_opt(match_opt_arg)

sql/sql_parse.cc

@@ -3958,13 +3958,13 @@ bool add_field_to_list(THD *thd, char *field_name, enum_field_types type,
   {
     lex->col_list.push_back(new key_part_spec(field_name,0));
     lex->key_list.push_back(new Key(Key::PRIMARY, NullS, HA_KEY_ALG_UNDEF,
-				    lex->col_list));
+				    0, lex->col_list));
     lex->col_list.empty();
   }
   if (type_modifier & (UNIQUE_FLAG | UNIQUE_KEY_FLAG))
   {
     lex->col_list.push_back(new key_part_spec(field_name,0));
-    lex->key_list.push_back(new Key(Key::UNIQUE, NullS, HA_KEY_ALG_UNDEF,
+    lex->key_list.push_back(new Key(Key::UNIQUE, NullS, HA_KEY_ALG_UNDEF, 0,
 				    lex->col_list));
     lex->col_list.empty();
   }

sql/sql_table.cc

@@ -679,14 +679,27 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
       DBUG_RETURN(-1);
     }
     key_iterator2.rewind ();
-    while ((key2 = key_iterator2++) != key)
+    if (key->type != Key::FOREIGN_KEY)
     {
-      if (*key == *key2)
+      while ((key2 = key_iterator2++) != key)
       {
-	/* TO DO: issue warning message */
-	/* mark that the key should be ignored */
-	key->name=ignore_key;
-	break;
+        if ((key2->type != Key::FOREIGN_KEY && !foreign_key_prefix(key, key2)))
+        {
+          /* TO DO: issue warning message */
+          /* mark that the generated key should be ignored */
+          if (!key2->generated ||
+              (key->generated && key->columns.elements <
+               key2->columns.elements))
+            key->name= ignore_key;
+          else
+          {
+            /* Remove the previous, generated key */
+            key2->name= ignore_key;
+            key_parts-= key2->columns.elements;
+            (*key_count)--;
+          }
+          break;
+        }
       }
     }
     if (key->name != ignore_key)
@@ -731,14 +744,14 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
 
     switch(key->type){
     case Key::MULTIPLE:
-	key_info->flags = 0;
+	key_info->flags= 0;
 	break;
     case Key::FULLTEXT:
-	key_info->flags = HA_FULLTEXT;
+	key_info->flags= HA_FULLTEXT;
 	break;
     case Key::SPATIAL:
 #ifdef HAVE_SPATIAL
-	key_info->flags = HA_SPATIAL;
+	key_info->flags= HA_SPATIAL;
 	break;
 #else
 	my_printf_error(ER_FEATURE_DISABLED,ER(ER_FEATURE_DISABLED),MYF(0),
@@ -749,8 +762,11 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
       key_number--;				// Skip this key
       continue;
     default:
-	key_info->flags = HA_NOSAME;
+      key_info->flags = HA_NOSAME;
+      break;
     }
+    if (key->generated)
+      key_info->flags|= HA_GENERATED_KEY;
 
     key_info->key_parts=(uint8) key->columns.elements;
     key_info->key_part=key_part_info;
@@ -774,7 +790,7 @@ int mysql_prepare_table(THD *thd, HA_CREATE_INFO *create_info,
     */
 
     /* TODO: Add proper checks if handler supports key_type and algorithm */
-    if (key_info->flags == HA_SPATIAL)
+    if (key_info->flags & HA_SPATIAL)
     {
       if (key_info->key_parts != 1)
       {
@@ -2824,6 +2840,7 @@ int mysql_alter_table(THD *thd,char *new_db, char *new_name,
 				   Key::FULLTEXT : Key::MULTIPLE)),
 				 key_name,
 				 key_info->algorithm,
+                                 test(key_info->flags & HA_GENERATED_KEY),
 				 key_parts));
   }
   {

sql/sql_yacc.yy

@@ -955,7 +955,7 @@ create:
 	  {
 	    LEX *lex=Lex;
 
-	    lex->key_list.push_back(new Key($2,$4.str, $5, lex->col_list));
+	    lex->key_list.push_back(new Key($2,$4.str, $5, 0, lex->col_list));
 	    lex->col_list.empty();
 	  }
 	| CREATE DATABASE opt_if_not_exists ident
@@ -1187,14 +1187,15 @@ key_def:
 	key_type opt_ident key_alg '(' key_list ')'
 	  {
 	    LEX *lex=Lex;
-	    lex->key_list.push_back(new Key($1,$2, $3, lex->col_list));
+	    lex->key_list.push_back(new Key($1,$2, $3, 0, lex->col_list));
 	    lex->col_list.empty();		/* Alloced by sql_alloc */
 	  }
 	| opt_constraint constraint_key_type opt_ident key_alg '(' key_list ')'
 	  {
 	    LEX *lex=Lex;
 	    const char *key_name= $3 ? $3:$1;
-	    lex->key_list.push_back(new Key($2, key_name, $4, lex->col_list));
+	    lex->key_list.push_back(new Key($2, key_name, $4, 0,
+				    lex->col_list));
 	    lex->col_list.empty();		/* Alloced by sql_alloc */
 	  }
 	| opt_constraint FOREIGN KEY_SYM opt_ident '(' key_list ')' references
@@ -1206,8 +1207,9 @@ key_def:
 				    lex->fk_delete_opt,
 				    lex->fk_update_opt,
 				    lex->fk_match_option));
-	    lex->key_list.push_back(new Key(Key::MULTIPLE, $4 ? $4:$1,
-					    HA_KEY_ALG_UNDEF, lex->col_list));
+	    lex->key_list.push_back(new Key(Key::MULTIPLE, $4 ? $4 : $1,
+					    HA_KEY_ALG_UNDEF, 1,
+					    lex->col_list));
 	    lex->col_list.empty();		/* Alloced by sql_alloc */
 	  }
 	| constraint opt_check_constraint

strings/strings-x86.s

@@ -43,7 +43,9 @@ bmove_align:
 .ba_20:	pop	%esi
 	movl	%edx,%edi
 	ret
-	.size	 bmove_align,.end-bmove_align
+
+.bmove_align_end:	
+	.size	 bmove_align,.bmove_align_end-bmove_align
 
 	# Move a string from higher to lower
 	# Arg from_end+1,to_end+1,length