diff --git a/lib/Doctrine/Hydrate.php b/lib/Doctrine/Hydrate.php
index a7590d2df..d182ec8b0 100644
--- a/lib/Doctrine/Hydrate.php
+++ b/lib/Doctrine/Hydrate.php
@@ -66,7 +66,7 @@ class Doctrine_Hydrate
     /**
      * @var Doctrine_Connection $conn           Doctrine_Connection object
      */
-    protected $conn;
+    protected $_conn;
     /**
      * @var Doctrine_View $_view                Doctrine_View object, when set this object will use the
      *                                          the query given by the view object for object population
@@ -94,11 +94,6 @@ class Doctrine_Hydrate
      *                                      and values as sql aliases
      */
     protected $aggregateMap      = array();
-    /**
-     * @var Doctrine_Hydrate_Alias $aliasHandler    handles the creation and storage of table aliases and
-     *                                              binds the aliases to component aliases / paths
-     */
-    protected $aliasHandler;
     /**
      * @var array $parts            SQL query string parts
      */
@@ -136,7 +131,7 @@ class Doctrine_Hydrate
         if ( ! ($connection instanceof Doctrine_Connection)) {
             $connection = Doctrine_Manager::getInstance()->getCurrentConnection();
         }
-        $this->conn = $connection;
+        $this->_conn = $connection;
     }
     public function generateNewAlias($alias)
     {
@@ -262,10 +257,16 @@ class Doctrine_Hydrate
     }
     /**
      * copyAliases
+     * copy aliases from another Hydrate object
      *
-     * @return void
+     * this method is needed by DQL subqueries which need the aliases
+     * of the parent query
+     *
+     * @param Doctrine_Hydrate $query   the query object from which the
+     *                                  aliases are copied from
+     * @return Doctrine_Hydrate         this object
      */
-    public function copyAliases($query)
+    public function copyAliases(Doctrine_Hydrate $query)
     {
         $this->shortAliases = $query->shortAliases;
 
@@ -273,6 +274,7 @@ class Doctrine_Hydrate
     }
     /**
      * createSubquery
+     * creates a subquery
      *
      * @return Doctrine_Hydrate
      */
@@ -353,7 +355,7 @@ class Doctrine_Hydrate
      */
     public function getConnection()
     {
-        return $this->conn;
+        return $this->_conn;
     }
     /**
      * setView
@@ -443,7 +445,7 @@ class Doctrine_Hydrate
      */
     public function execute($params = array(), $return = Doctrine::FETCH_RECORD)
     {
-        $params = $this->conn->convertBooleans(array_merge($this->params, $params));
+        $params = $this->_conn->convertBooleans(array_merge($this->params, $params));
         $params = $this->convertEnums($params);
 
         if ( ! $this->_view) {
@@ -453,16 +455,16 @@ class Doctrine_Hydrate
         }
 
         if ($this->isLimitSubqueryUsed() &&
-            $this->conn->getDBH()->getAttribute(Doctrine::ATTR_DRIVER_NAME) !== 'mysql') {
+            $this->_conn->getDBH()->getAttribute(Doctrine::ATTR_DRIVER_NAME) !== 'mysql') {
 
             $params = array_merge($params, $params);
         }
 
         if ($this->type !== self::SELECT) {
-            return $this->conn->exec($query, $params);
+            return $this->_conn->exec($query, $params);
         }
 
-        $stmt  = $this->conn->execute($query, $params);
+        $stmt  = $this->_conn->execute($query, $params);
         $array = (array) $this->parseData($stmt);
         if (empty($this->_aliasMap)) {
             throw new Doctrine_Hydrate_Exception("Couldn't execute query. Component alias map was empty.");
diff --git a/lib/Doctrine/Query.php b/lib/Doctrine/Query.php
index bee0eca63..137c3e239 100644
--- a/lib/Doctrine/Query.php
+++ b/lib/Doctrine/Query.php
@@ -379,7 +379,7 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
             $argStr = substr($func, ($pos + 1), -1);
             $args   = explode(',', $argStr);
     
-            $func   = call_user_func_array(array($this->conn->expression, $name), $args);
+            $func   = call_user_func_array(array($this->_conn->expression, $name), $args);
     
             if(substr($func, 0, 1) !== '(') {
                 $pos  = strpos($func, '(');
@@ -641,10 +641,10 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
                 $subquery = $this->getLimitSubquery();
 
 
-                switch (strtolower($this->conn->getName())) {
+                switch (strtolower($this->_conn->getName())) {
                     case 'mysql':
                         // mysql doesn't support LIMIT in subqueries
-                        $list     = $this->conn->execute($subquery, $params)->fetchAll(PDO::FETCH_COLUMN);
+                        $list     = $this->_conn->execute($subquery, $params)->fetchAll(PDO::FETCH_COLUMN);
                         $subquery = implode(', ', $list);
                         break;
                     case 'pgsql':
@@ -670,7 +670,7 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
         $q .= ( ! empty($this->parts['orderby']))? ' ORDER BY ' . implode(', ', $this->parts['orderby'])  : '';
 
         if ($modifyLimit) {
-            $q = $this->conn->modifyLimitQuery($q, $this->parts['limit'], $this->parts['offset']);
+            $q = $this->_conn->modifyLimitQuery($q, $this->parts['limit'], $this->parts['offset']);
         }
 
         // return to the previous state
@@ -710,7 +710,7 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
         // initialize the base of the subquery
         $subquery   = 'SELECT DISTINCT ' . $primaryKey;
 
-        if ($this->conn->getDBH()->getAttribute(PDO::ATTR_DRIVER_NAME) == 'pgsql') {
+        if ($this->_conn->getDBH()->getAttribute(PDO::ATTR_DRIVER_NAME) == 'pgsql') {
             // pgsql needs the order by fields to be preserved in select clause
 
             foreach ($this->parts['orderby'] as $part) {
@@ -746,7 +746,7 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
         $subquery .= ( ! empty($this->parts['orderby']))? ' ORDER BY ' . implode(', ', $this->parts['orderby'])   : '';
 
         // add driver specific limit clause
-        $subquery = $this->conn->modifyLimitQuery($subquery, $this->parts['limit'], $this->parts['offset']);
+        $subquery = $this->_conn->modifyLimitQuery($subquery, $this->parts['limit'], $this->parts['offset']);
 
         $parts = Doctrine_Tokenizer::quoteExplode($subquery, ' ', "'", "'");
 
@@ -972,8 +972,8 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
 
                 $localAlias   = $this->getShortAlias($parent, $table->getTableName());
                 $foreignAlias = $this->getShortAlias($componentAlias, $relation->getTable()->getTableName());
-                $localSql     = $this->conn->quoteIdentifier($table->getTableName()) . ' ' . $localAlias;
-                $foreignSql   = $this->conn->quoteIdentifier($relation->getTable()->getTableName()) . ' ' . $foreignAlias;
+                $localSql     = $this->_conn->quoteIdentifier($table->getTableName()) . ' ' . $localAlias;
+                $foreignSql   = $this->_conn->quoteIdentifier($relation->getTable()->getTableName()) . ' ' . $foreignAlias;
 
                 $map = $relation->getTable()->inheritanceMap;
   
@@ -1063,16 +1063,16 @@ class Doctrine_Query extends Doctrine_Query_Abstract implements Countable
     public function loadRoot($name, $componentAlias)
     {
     	// get the connection for the component
-        $this->conn = Doctrine_Manager::getInstance()
+        $this->_conn = Doctrine_Manager::getInstance()
                       ->getConnectionForComponent($name);
 
-        $table = $this->conn->getTable($name);
+        $table = $this->_conn->getTable($name);
         $tableName = $table->getTableName();
 
         // get the short alias for this table
         $tableAlias = $this->getShortAlias($componentAlias, $tableName);
         // quote table name
-        $queryPart = $this->conn->quoteIdentifier($tableName);
+        $queryPart = $this->_conn->quoteIdentifier($tableName);
 
         if ($this->type === self::SELECT) {
             $queryPart .= ' ' . $tableAlias;