Index: includes/database/query.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/query.inc,v
retrieving revision 1.55
diff -u -r1.55 query.inc
--- includes/database/query.inc	5 Aug 2010 08:26:35 -0000	1.55
+++ includes/database/query.inc	28 Aug 2010 05:15:50 -0000
@@ -247,12 +247,33 @@
    */
   protected $comments = array();
 
+  /**
+   * Query hints or flags that can be set on a query.
+   *
+   * @var string
+   */
+  protected $hints = '';
+
   public function __construct(DatabaseConnection $connection, $options) {
     $this->connection = $connection;
     $this->queryOptions = $options;
   }
 
   /**
+   * Sets the hints or flags on a query.
+   *
+   * Hints and flags directly affect the way in which the query is run
+   * on the database server. Their syntax is database specific, so they
+   * should be used internally in database-specific classes only.
+   *
+   * @param $hints
+   *   The hint string to be inserted into the query.
+   */
+  public function setHints($hints) {
+    $this->hints = $hints;
+  }
+
+  /**
    * Run the query against the database.
    */
   abstract protected function execute();
Index: includes/database/select.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/select.inc,v
retrieving revision 1.45
diff -u -r1.45 select.inc
--- includes/database/select.inc	8 Aug 2010 02:18:53 -0000	1.45
+++ includes/database/select.inc	28 Aug 2010 05:15:50 -0000
@@ -1357,8 +1357,11 @@
     // Create a comments string to prepend to the query.
     $comments = (!empty($this->comments)) ? '/* ' . implode('; ', $this->comments) . ' */ ' : '';
 
+    // Create a hints string to include in the query.
+    $hints = (!empty($this->hints)) ? $this->hints . ' ' : '';
+
     // SELECT
-    $query = $comments . 'SELECT ';
+    $query = $comments . 'SELECT ' . $hints;
     if ($this->distinct) {
       $query .= 'DISTINCT ';
     }
Index: includes/database/mysql/query.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/mysql/query.inc,v
retrieving revision 1.18
diff -u -r1.18 query.inc
--- includes/database/mysql/query.inc	26 Jun 2010 01:40:05 -0000	1.18
+++ includes/database/mysql/query.inc	28 Aug 2010 05:15:50 -0000
@@ -46,16 +46,19 @@
     // Create a comments string to prepend to the query.
     $comments = (!empty($this->comments)) ? '/* ' . implode('; ', $this->comments) . ' */ ' : '';
 
+    // Create a hints string to include in the query.
+    $hints = (!empty($this->hints)) ? $this->hints . ' ' : '';
+
     // Default fields are always placed first for consistency.
     $insert_fields = array_merge($this->defaultFields, $this->insertFields);
 
     // If we're selecting from a SelectQuery, finish building the query and
     // pass it back, as any remaining options are irrelevant.
     if (!empty($this->fromQuery)) {
-      return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
+      return $comments . 'INSERT ' . $hints . 'INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
     }
 
-    $query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
+    $query = $comments . 'INSERT ' . $hints . 'INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
 
     $max_placeholder = 0;
     $values = array();
Index: includes/database/pgsql/query.inc
===================================================================
RCS file: /cvs/drupal/drupal/includes/database/pgsql/query.inc,v
retrieving revision 1.20
diff -u -r1.20 query.inc
--- includes/database/pgsql/query.inc	27 Aug 2010 15:53:43 -0000	1.20
+++ includes/database/pgsql/query.inc	28 Aug 2010 05:15:50 -0000
@@ -107,16 +107,19 @@
     // Create a comments string to prepend to the query.
     $comments = (!empty($this->comments)) ? '/* ' . implode('; ', $this->comments) . ' */ ' : '';
 
+    // Create a hints string to include in the query.
+    $hints = (!empty($this->hints)) ? $this->hints . ' ' : '';
+
     // Default fields are always placed first for consistency.
     $insert_fields = array_merge($this->defaultFields, $this->insertFields);
 
     // If we're selecting from a SelectQuery, finish building the query and
     // pass it back, as any remaining options are irrelevant.
     if (!empty($this->fromQuery)) {
-      return $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
+      return $comments . 'INSERT ' . $hints . 'INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') ' . $this->fromQuery;
     }
 
-    $query = $comments . 'INSERT INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
+    $query = $comments . 'INSERT ' . $hints . 'INTO {' . $this->table . '} (' . implode(', ', $insert_fields) . ') VALUES ';
 
     $max_placeholder = 0;
     $values = array();