Bugfix when using a multi-part unique key in the SET and WHERE part

Put PRIMARY KEY and UNIQUE keys before other keys
Fixes for auto_increment keys for BDB tables


Docs/manual.texi:
  Changelog
sql/ha_berkeley.cc:
  Fixes for auto_increment keys
sql/sql_table.cc:
  Put PRIMARY KEY and UNIQUE keys before other keys
sql/sql_update.cc:
  Bugfix when using a multi-part unique key in the SET and WHERE part

Docs/manual.texi

@@ -17896,6 +17896,11 @@ tables as one. This only works with MERGE tables. @xref{MERGE}.
 For the moment you need to have @code{SELECT}, @code{UPDATE}, and
 @code{DELETE} privileges on the tables you map to a @code{MERGE} table.
 All mapped tables must be in the same database as the @code{MERGE} table.
+@item
+In the created table the @code{PRIMARY} key will be placed first, followed
+by all @code{UNIQUE} keys and then the normal keys.  This helps the
+@strong{MySQL} optimizer to prioritize which key to use and also more quickly
+detect duplicated @code{UNIQUE} keys.
 @end itemize
 
 @cindex silent column changes
@@ -22597,7 +22602,7 @@ You may also want to change @code{binlog_cache_size} and
 @itemize @bullet
 @item
 @strong{MySQL} requires a @code{PRIMARY KEY} in each BDB table to be
-able to refer to previously read rows. If you don't create on,
+able to refer to previously read rows. If you don't create one,
 @strong{MySQL} will create an maintain a hidden @code{PRIMARY KEY} for
 you.  The hidden key has a length of 5 bytes and is incremented for each
 insert attempt.
@@ -22617,8 +22622,6 @@ you don't use @code{LOCK TABLE}, @strong{MYSQL} will issue an internal
 multiple-write lock on the table to ensure that the table will be
 properly locked if another thread issues a table lock.
 @item
-@code{ALTER TABLE} doesn't yet work on @code{BDB} tables.
-@item
 Internal locking in @code{BDB} tables is done on page level.
 @item
 @code{SELECT COUNT(*) FROM table_name} is slow as @code{BDB} tables doesn't
@@ -22636,8 +22639,8 @@ tables. In other words, the key information will take a little more
 space in @code{BDB} tables compared to MyISAM tables which don't use
 @code{PACK_KEYS=0}.
 @item
-There is often holes in the BDB table to allow you to insert new rows
-between different keys.  This makes BDB tables somewhat larger than
+There is often holes in the BDB table to allow you to insert new rows in
+the middle of the key tree.  This makes BDB tables somewhat larger than
 MyISAM tables.
 @item
 @strong{MySQL} performs a checkpoint each time a new Berkeley DB log
@@ -39636,6 +39639,14 @@ though, so Version 3.23 is not released as a stable version yet.
 @appendixsubsec Changes in release 3.23.29
 @itemize @bullet
 @item
+When creating a table, put @code{PRIMARY} keys first, followed by
+@code{UNIQUE} keys.
+@item
+Fixed a bug in @code{UPDATE} involving multi-part keys where one
+specified all key parts both in the update and the @code{WHERE} part. In
+this case @strong{MySQL} could try to update a record that didn't match
+the whole @code{WHERE} part.
+@item
 Changed drop table to first drop the tables and then the @code{.frm} file.
 @item
 Fixed a bug in the hostname cache which caused @code{mysqld} to report the

sql/ha_berkeley.cc

@@ -1660,7 +1660,8 @@ longlong ha_berkeley::get_auto_increment()
   }
   else
   {
-    DBT row;
+    DBT row,old_key;
+    DBC *auto_cursor;
     bzero((char*) &row,sizeof(row));
     uint key_len;
     KEY *key_info= &table->key_info[active_index];
@@ -1670,27 +1671,37 @@ longlong ha_berkeley::get_auto_increment()
 			    key_buff, table->record[0],
 			    table->next_number_key_offset);
     /* Store for compare */
-    memcpy(key_buff2, key_buff, (key_len=last_key.size));
-    /* Modify the compare so that we will find the next key */
-    key_info->handler.bdb_return_if_eq= 1;
-    /* We lock the next key as the new key will probl. be on the same page */
-    error=cursor->c_get(cursor, &last_key, &row, DB_SET_RANGE | DB_RMW),
-    key_info->handler.bdb_return_if_eq= 0;
-    
-    if (!error || error == DB_NOTFOUND)
+    memcpy(old_key.data=key_buff2, key_buff, (old_key.size=last_key.size));
+    error=1;
+    if (!(file->cursor(key_file[active_index], transaction, &auto_cursor, 0)))
     {
-      /*
-	Now search go one step back and then we should have found the
-	biggest key with the given prefix
-      */
-      if (read_row(cursor->c_get(cursor, &last_key, &row, DB_PREV | DB_RMW),
-		   table->record[1], active_index, &row, (DBT*) 0, 0) ||
-	  berkeley_key_cmp(table, key_info, key_buff2, key_len))
-	error=1;			// Something went wrong or no such key
+      /* Modify the compare so that we will find the next key */
+      key_info->handler.bdb_return_if_eq= 1;
+      /* We lock the next key as the new key will probl. be on the same page */
+      error=auto_cursor->c_get(auto_cursor, &last_key, &row,
+			       DB_SET_RANGE | DB_RMW);
+      key_info->handler.bdb_return_if_eq= 0;
+      if (!error || error == DB_NOTFOUND)
+      {
+	/*
+	  Now search go one step back and then we should have found the
+	  biggest key with the given prefix
+	  */
+	error=1;
+	if (!auto_cursor->c_get(auto_cursor, &last_key, &row, DB_PREV | DB_RMW)
+	    && !berkeley_cmp_packed_key(key_file[active_index], &old_key,
+					&last_key))
+	{
+	  error=0;				// Found value
+	  unpack_key(table->record[1], &last_key, active_index);
+	}
+      }
+      auto_cursor->c_close(auto_cursor);
     }
   }
-  nr=(longlong)
-    table->next_number_field->val_int_offset(table->rec_buff_length)+1;
+  if (!error)
+    nr=(longlong)
+      table->next_number_field->val_int_offset(table->rec_buff_length)+1;
   ha_berkeley::index_end();
   (void) ha_berkeley::extra(HA_EXTRA_NO_KEYREAD);
   return nr;

sql/sql_table.cc

@@ -327,18 +327,28 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
   }
 
   /* Create keys */
+
   List_iterator<Key> key_iterator(keys);
   uint key_parts=0,key_count=keys.elements;
-  bool primary_key=0,unique_key=0;
+  List<Key> keys_in_order;			// Add new keys here
+  Key *primary_key=0;
+  bool unique_key=0;
   Key *key;
   uint tmp;
   tmp=min(file->max_keys(), MAX_KEY);
-
   if (key_count > tmp)
   {
     my_error(ER_TOO_MANY_KEYS,MYF(0),tmp);
     DBUG_RETURN(-1);
   }
+
+  /*
+    Check keys;
+    Put PRIMARY KEY first, then UNIQUE keys and other keys last
+    This will make checking for duplicated keys faster and ensure that
+    primary keys are prioritized.
+  */
+
   while ((key=key_iterator++))
   {
     tmp=max(file->max_key_parts(),MAX_REF_PARTS);
@@ -353,17 +363,6 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
       DBUG_RETURN(-1);
     }
     key_parts+=key->columns.elements;
-  }
-  key_info_buffer=key_info=(KEY*) sql_calloc(sizeof(KEY)*key_count);
-  key_part_info=(KEY_PART_INFO*) sql_calloc(sizeof(KEY_PART_INFO)*key_parts);
-  if (!key_info_buffer || ! key_part_info)
-    DBUG_RETURN(-1);				// Out of memory
-
-  key_iterator.rewind();
-  for (; (key=key_iterator++) ; key_info++)
-  {
-    uint key_length=0;
-    key_part_spec *column;
     if (key->type == Key::PRIMARY)
     {
       if (primary_key)
@@ -371,10 +370,39 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
 	my_error(ER_MULTIPLE_PRI_KEY,MYF(0));
 	DBUG_RETURN(-1);
       }
-      primary_key=1;
+      primary_key=key;
     }
     else if (key->type == Key::UNIQUE)
+    {
       unique_key=1;
+      if (keys_in_order.push_front(key))
+	DBUG_RETURN(-1);
+    }
+    else if (keys_in_order.push_back(key))
+      DBUG_RETURN(-1);
+  }
+  if (primary_key)
+  {
+    if (keys_in_order.push_front(primary_key))
+      DBUG_RETURN(-1);
+  }
+  else if (!unique_key && (file->option_flag() & HA_REQUIRE_PRIMARY_KEY))
+  {
+    my_error(ER_REQUIRES_PRIMARY_KEY,MYF(0));
+    DBUG_RETURN(-1);
+  }
+
+  key_info_buffer=key_info=(KEY*) sql_calloc(sizeof(KEY)*key_count);
+  key_part_info=(KEY_PART_INFO*) sql_calloc(sizeof(KEY_PART_INFO)*key_parts);
+  if (!key_info_buffer || ! key_part_info)
+    DBUG_RETURN(-1);				// Out of memory
+
+  List_iterator<Key> key_iterator_in_order(keys_in_order);
+  for (; (key=key_iterator_in_order++) ; key_info++)
+  {
+    uint key_length=0;
+    key_part_spec *column;
+
     key_info->flags= (key->type == Key::MULTIPLE) ? 0 :
                      (key->type == Key::FULLTEXT) ? HA_FULLTEXT : HA_NOSAME;
     key_info->key_parts=(uint8) key->columns.elements;
@@ -508,12 +536,6 @@ int mysql_create_table(THD *thd,const char *db, const char *table_name,
     my_error(ER_WRONG_AUTO_KEY,MYF(0));
     DBUG_RETURN(-1);
   }
-  if (!primary_key && !unique_key &&
-      (file->option_flag() & HA_REQUIRE_PRIMARY_KEY))
-  {
-    my_error(ER_REQUIRES_PRIMARY_KEY,MYF(0));
-    DBUG_RETURN(-1);
-  }
 
       /* Check if table exists */
   if (create_info->options & HA_LEX_CREATE_TMP_TABLE)

sql/sql_update.cc

@@ -75,8 +75,16 @@ int mysql_update(THD *thd,TABLE_LIST *table_list,List<Item> &fields,
   if (table->timestamp_field &&			// Don't set timestamp if used
       table->timestamp_field->query_id == thd->query_id)
     table->time_stamp=0;
+
+  /* Reset the query_id string so that ->used_keys is based on the WHERE */
+
   table->used_keys=table->keys_in_use;
   table->quick_keys=0;
+  reg2 Item *item;
+  List_iterator<Item> it(fields);  
+  ulong query_id=thd->query_id-1;
+  while ((item=it++))
+    ((Item_field*) item)->field->query_id=query_id;
   if (setup_fields(thd,table_list,values,0,0) ||
       setup_conds(thd,table_list,&conds))
   {
@@ -84,7 +92,8 @@ int mysql_update(THD *thd,TABLE_LIST *table_list,List<Item> &fields,
     DBUG_RETURN(-1);				/* purecov: inspected */
   }
   old_used_keys=table->used_keys;
-  table->used_keys=0;				// Can't use 'only index'
+  // Don't count on usage of 'only index' when calculating which key to use
+  table->used_keys=0;
   select=make_select(table,0,0,conds,&error);
   if (error ||
       (select && select->check_quick(test(thd->options & SQL_SAFE_UPDATES),