diff --git a/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php b/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php
index 1cbed0229..d9b1e201c 100644
--- a/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php
+++ b/lib/Doctrine/ORM/Internal/Hydration/AbstractHydrator.php
@@ -174,26 +174,26 @@ abstract class AbstractHydrator
         foreach ($data as $key => $value) {
             // Parse each column name only once. Cache the results.
             if ( ! isset($cache[$key])) {
-                if ($this->_resultSetMapping->isIgnoredColumn($key)) {
+                if (isset($this->_resultSetMapping->ignoredColumns[$key])) {
                     $cache[$key] = false;
-                } else if ($this->_resultSetMapping->isScalarResult($key)) {
+                } else if (isset($this->_resultSetMapping->scalarMappings[$key])) {
                     $cache[$key]['fieldName'] = $this->_resultSetMapping->getScalarAlias($key);
                     $cache[$key]['isScalar'] = true;
-                } else if ($this->_resultSetMapping->isFieldResult($key)) {
+                } else if (isset($this->_resultSetMapping->fieldMappings[$key])) {
                     $classMetadata = $this->_resultSetMapping->getOwningClass($key);
-                    $fieldName = $this->_resultSetMapping->getFieldName($key);
+                    $fieldName = $this->_resultSetMapping->fieldMappings[$key];
                     $classMetadata = $this->_lookupDeclaringClass($classMetadata, $fieldName);
                     $cache[$key]['fieldName'] = $fieldName;
                     $cache[$key]['isScalar'] = false;
                     $cache[$key]['type'] = Type::getType($classMetadata->getTypeOfField($fieldName));
                     $cache[$key]['isIdentifier'] = $classMetadata->isIdentifier($fieldName);
-                    $cache[$key]['dqlAlias'] = $this->_resultSetMapping->getEntityAlias($key);
+                    $cache[$key]['dqlAlias'] = $this->_resultSetMapping->columnOwnerMap[$key];
                 } else {
                     // Discriminator column
                     $cache[$key]['isDiscriminator'] = true;
                     $cache[$key]['isScalar'] = false;
                     $cache[$key]['fieldName'] = $key;
-                    $cache[$key]['dqlAlias'] = $this->_resultSetMapping->getEntityAlias($key);
+                    $cache[$key]['dqlAlias'] = $this->_resultSetMapping->columnOwnerMap[$key];
                 }
             }
 
@@ -245,21 +245,20 @@ abstract class AbstractHydrator
         foreach ($data as $key => $value) {
             // Parse each column name only once. Cache the results.
             if ( ! isset($cache[$key])) {
-                if ($this->_resultSetMapping->isIgnoredColumn($key)) {
+                if (isset($this->_resultSetMapping->ignoredColumns[$key])) {
                     $cache[$key] = false;
                     continue;
-                } else if ($this->_resultSetMapping->isScalarResult($key)) {
-                    $cache[$key]['fieldName'] = $this->_resultSetMapping->getScalarAlias($key);
+                } else if (isset($this->_resultSetMapping->scalarMappings[$key])) {
+                    $cache[$key]['fieldName'] = $this->_resultSetMapping->scalarMappings[$key];
                     $cache[$key]['isScalar'] = true;
                 } else {
                     $classMetadata = $this->_resultSetMapping->getOwningClass($key);
-                    $fieldName = $this->_resultSetMapping->getFieldName($key);
+                    $fieldName = $this->_resultSetMapping->fieldMappings[$key];
                     $classMetadata = $this->_lookupDeclaringClass($classMetadata, $fieldName);
-                    //$fieldName = $classMetadata->getFieldNameForLowerColumnName($columnName);
                     $cache[$key]['fieldName'] = $fieldName;
                     $cache[$key]['isScalar'] = false;
                     $cache[$key]['type'] = Type::getType($classMetadata->getTypeOfField($fieldName));
-                    $cache[$key]['dqlAlias'] = $this->_resultSetMapping->getEntityAlias($key);
+                    $cache[$key]['dqlAlias'] = $this->_resultSetMapping->columnOwnerMap[$key];
                 }
             }
             
@@ -284,8 +283,8 @@ abstract class AbstractHydrator
      */
     protected function _getCustomIndexField($alias)
     {
-        return $this->_resultSetMapping->hasIndexBy($alias) ?
-                $this->_resultSetMapping->getIndexByField($alias) : null;
+        return isset($this->_resultSetMapping->indexByMap[$alias]) ?
+                $this->_resultSetMapping->indexByMap[$alias] : null;
     }
 
     /**
diff --git a/lib/Doctrine/ORM/Internal/Hydration/ArrayHydrator.php b/lib/Doctrine/ORM/Internal/Hydration/ArrayHydrator.php
index 19f5fef7a..16469973a 100644
--- a/lib/Doctrine/ORM/Internal/Hydration/ArrayHydrator.php
+++ b/lib/Doctrine/ORM/Internal/Hydration/ArrayHydrator.php
@@ -88,16 +88,17 @@ class ArrayHydrator extends AbstractHydrator
         foreach ($rowData as $dqlAlias => $data) {
             $index = false;
 
-            if ($this->_resultSetMapping->hasParentAlias($dqlAlias)) {
+            if (isset($this->_resultSetMapping->parentAliasMap[$dqlAlias])) {
+                // It's a joined result
 
-                $parent = $this->_resultSetMapping->getParentAlias($dqlAlias);
-                $relation = $this->_resultSetMapping->getRelation($dqlAlias);
+                $parent = $this->_resultSetMapping->parentAliasMap[$dqlAlias];
+                $relation = $this->_resultSetMapping->relationMap[$dqlAlias];
                 $relationAlias = $relation->getSourceFieldName();
                 $path = $parent . '.' . $dqlAlias;
 
                 // Get a reference to the right element in the result tree.
                 // This element will get the associated element attached.
-                if ($this->_resultSetMapping->isMixedResult() && isset($this->_rootAliases[$parent])) {
+                if ($this->_resultSetMapping->isMixed && isset($this->_rootAliases[$parent])) {
                     $key = key(reset($this->_resultPointers));
                     // TODO: Exception if $key === null ?
                     $baseElement =& $this->_resultPointers[$parent][$key];
@@ -154,14 +155,14 @@ class ArrayHydrator extends AbstractHydrator
                 if ($this->_isSimpleQuery || ! isset($this->_identifierMap[$dqlAlias][$id[$dqlAlias]])) {
                     $element = $rowData[$dqlAlias];
                     if ($field = $this->_getCustomIndexField($dqlAlias)) {
-                        if ($this->_resultSetMapping->isMixedResult()) {
+                        if ($this->_resultSetMapping->isMixed) {
                             $result[] = array($element[$field] => $element);
                             ++$this->_resultCounter;
                         } else {
                             $result[$element[$field]] = $element;
                         }
                     } else {
-                        if ($this->_resultSetMapping->isMixedResult()) {
+                        if ($this->_resultSetMapping->isMixed) {
                             $result[] = array($element);
                             ++$this->_resultCounter;
                         } else {
diff --git a/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php b/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php
index ae76fb4df..e8561931f 100644
--- a/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php
+++ b/lib/Doctrine/ORM/Internal/Hydration/ObjectHydrator.php
@@ -53,13 +53,13 @@ class ObjectHydrator extends AbstractHydrator
     /** @override */
     protected function _prepare()
     {
-        $this->_isSimpleQuery = $this->_resultSetMapping->getEntityResultCount() <= 1;
+        $this->_isSimpleQuery = count($this->_resultSetMapping->aliasMap) <= 1;
         $this->_allowPartialObjects = $this->_em->getConfiguration()->getAllowPartialObjects();
         $this->_identifierMap = array();
         $this->_resultPointers = array();
         $this->_idTemplate = array();
         $this->_resultCounter = 0;
-        foreach ($this->_resultSetMapping->getAliasMap() as $dqlAlias => $class) {
+        foreach ($this->_resultSetMapping->aliasMap as $dqlAlias => $class) {
             $this->_identifierMap[$dqlAlias] = array();
             $this->_resultPointers[$dqlAlias] = array();
             $this->_idTemplate[$dqlAlias] = '';
@@ -73,8 +73,8 @@ class ObjectHydrator extends AbstractHydrator
                     $this->_discriminatorMap[$class->name][$value] = $className;
                 }
             }
-            if ($this->_resultSetMapping->isRelation($dqlAlias)) {
-                $assoc = $this->_resultSetMapping->getRelation($dqlAlias);
+            if (isset($this->_resultSetMapping->relationMap[$dqlAlias])) {
+                $assoc = $this->_resultSetMapping->relationMap[$dqlAlias];
                 $this->_fetchedAssociations[$assoc->getSourceEntityName()][$assoc->getSourceFieldName()] = true;
                 if ($mappedByField = $assoc->getMappedByFieldName()) {
                     $this->_fetchedAssociations[$assoc->getTargetEntityName()][$mappedByField] = true;
@@ -97,7 +97,7 @@ class ObjectHydrator extends AbstractHydrator
     {
         $s = microtime(true);
         
-        if ($this->_resultSetMapping->isMixedResult()) {
+        if ($this->_resultSetMapping->isMixed) {
             $result = array();
         } else {
             $result = new Collection;
@@ -226,7 +226,8 @@ class ObjectHydrator extends AbstractHydrator
 
     private function getEntity(array $data, $className)
     {
-        if ($discrColumn = $this->_resultSetMapping->getDiscriminatorColumn($className)) {
+        if (isset($this->_resultSetMapping->discriminatorColumns[$className])) {
+            $discrColumn = $this->_resultSetMapping->discriminatorColumns[$className];
             $className = $this->_discriminatorMap[$className][$data[$discrColumn]];
             unset($data[$discrColumn]);
         }
@@ -321,18 +322,18 @@ class ObjectHydrator extends AbstractHydrator
         // Hydrate the entity data found in the current row.
         foreach ($rowData as $dqlAlias => $data) {
             $index = false;
-            $entityName = $this->_resultSetMapping->getClass($dqlAlias)->name;
+            $entityName = $this->_resultSetMapping->aliasMap[$dqlAlias]->name;
             
-            if ($this->_resultSetMapping->hasParentAlias($dqlAlias)) {
+            if (isset($this->_resultSetMapping->parentAliasMap[$dqlAlias])) {
                 // It's a joined result
                 
-                $parent = $this->_resultSetMapping->getParentAlias($dqlAlias);
-                $relation = $this->_resultSetMapping->getRelation($dqlAlias);
+                $parent = $this->_resultSetMapping->parentAliasMap[$dqlAlias];
+                $relation = $this->_resultSetMapping->relationMap[$dqlAlias];
                 $relationAlias = $relation->getSourceFieldName();
 
                 // Get a reference to the right element in the result tree.
                 // This element will get the associated element attached.
-                if ($this->_resultSetMapping->isMixedResult() && isset($this->_rootAliases[$parent])) {
+                if ($this->_resultSetMapping->isMixed && isset($this->_rootAliases[$parent])) {
                     $key = key(reset($this->_resultPointers));
                     // TODO: Exception if $key === null ?
                     $baseElement =& $this->_resultPointers[$parent][$key];
@@ -420,7 +421,7 @@ class ObjectHydrator extends AbstractHydrator
                 if ($this->_isSimpleQuery || ! isset($this->_identifierMap[$dqlAlias][$id[$dqlAlias]])) {
                     $element = $this->getEntity($rowData[$dqlAlias], $entityName);
                     if ($field = $this->_getCustomIndexField($dqlAlias)) {
-                        if ($this->_resultSetMapping->isMixedResult()) {
+                        if ($this->_resultSetMapping->isMixed) {
                             $result[] = array(
                                 $this->_classMetadatas[$entityName]
                                         ->reflFields[$field]
@@ -433,7 +434,7 @@ class ObjectHydrator extends AbstractHydrator
                                     ->getValue($element));
                         }
                     } else {
-                        if ($this->_resultSetMapping->isMixedResult()) {
+                        if ($this->_resultSetMapping->isMixed) {
                             $result[] = array($element);
                             ++$this->_resultCounter;
                         } else {
diff --git a/lib/Doctrine/ORM/Query/ResultSetMapping.php b/lib/Doctrine/ORM/Query/ResultSetMapping.php
index 446fdd5e8..d1312d306 100644
--- a/lib/Doctrine/ORM/Query/ResultSetMapping.php
+++ b/lib/Doctrine/ORM/Query/ResultSetMapping.php
@@ -24,31 +24,35 @@ namespace Doctrine\ORM\Query;
 /**
  * A ResultSetMapping describes how a result set of an SQL query maps to a Doctrine result.
  *
+ * IMPORTANT NOTE:
+ * The properties of this class are only public for fast internal READ access.
+ * Users should use the public methods.
+ *
  * @author Roman Borschel <roman@code-factory.org>
  * @since 2.0
  */
 class ResultSetMapping
 {
     /** Whether the result is mixed (contains scalar values together with field values). */
-    private $_isMixed = false;
+    public $isMixed = false;
     /** Maps alias names to ClassMetadata descriptors. */
-    private $_aliasMap = array();
+    public $aliasMap = array();
     /** Maps alias names to related association mappings. */
-    private $_relationMap = array();
+    public $relationMap = array();
     /** Maps alias names to parent alias names. */
-    private $_parentAliasMap = array();
+    public $parentAliasMap = array();
     /** Maps column names in the result set to field names for each class. */
-    private $_fieldMappings = array();
+    public $fieldMappings = array();
     /** Maps column names in the result set to the alias to use in the mapped result. */
-    private $_scalarMappings = array();
+    public $scalarMappings = array();
     /** Maps column names in the result set to the alias they belong to. */
-    private $_columnOwnerMap = array();
+    public $columnOwnerMap = array();
     /** List of columns in the result set that are used as discriminator columns. */
-    private $_discriminatorColumns = array();
+    public $discriminatorColumns = array();
     /** Maps alias names to field names that should be used for indexing. */
-    private $_indexByMap = array();
+    public $indexByMap = array();
     /** A list of columns that should be ignored/skipped during hydration. */
-    private $_ignoredColumns = array();
+    public $ignoredColumns = array();
 
     /**
      *
@@ -58,55 +62,55 @@ class ResultSetMapping
      */
     public function addEntityResult($class, $alias)
     {
-        $this->_aliasMap[$alias] = $class;
+        $this->aliasMap[$alias] = $class;
     }
 
     public function setDiscriminatorColumn($className, $alias, $discrColumn)
     {
-        $this->_discriminatorColumns[$className] = $discrColumn;
-        $this->_columnOwnerMap[$discrColumn] = $alias;
+        $this->discriminatorColumns[$className] = $discrColumn;
+        $this->columnOwnerMap[$discrColumn] = $alias;
     }
 
     public function getDiscriminatorColumn($className)
     {
-        return isset($this->_discriminatorColumns[$className]) ?
-                $this->_discriminatorColumns[$className] : null;
+        return isset($this->discriminatorColumns[$className]) ?
+                $this->discriminatorColumns[$className] : null;
     }
 
     public function addIndexBy($alias, $fieldName)
     {
-        $this->_indexByMap[$alias] = $fieldName;
+        $this->indexByMap[$alias] = $fieldName;
     }
 
     public function hasIndexBy($alias)
     {
-        return isset($this->_indexByMap[$alias]);
+        return isset($this->indexByMap[$alias]);
     }
 
     public function getIndexByField($alias)
     {
-        return $this->_indexByMap[$alias];
+        return $this->indexByMap[$alias];
     }
 
     public function isFieldResult($columnName)
     {
-        return isset($this->_fieldMappings[$columnName]);
+        return isset($this->fieldMappings[$columnName]);
     }
 
     public function addFieldResult($alias, $columnName, $fieldName)
     {
-        $this->_fieldMappings[$columnName] = $fieldName;
-        $this->_columnOwnerMap[$columnName] = $alias;
-        if ( ! $this->_isMixed && $this->_scalarMappings) {
-            $this->_isMixed = true;
+        $this->fieldMappings[$columnName] = $fieldName;
+        $this->columnOwnerMap[$columnName] = $alias;
+        if ( ! $this->isMixed && $this->scalarMappings) {
+            $this->isMixed = true;
         }
     }
 
     public function addJoinedEntityResult($class, $alias, $parentAlias, $relation)
     {
-        $this->_aliasMap[$alias] = $class;
-        $this->_parentAliasMap[$alias] = $parentAlias;
-        $this->_relationMap[$alias] = $relation;
+        $this->aliasMap[$alias] = $class;
+        $this->parentAliasMap[$alias] = $parentAlias;
+        $this->relationMap[$alias] = $relation;
     }
 
     /*public function isDiscriminatorColumn($columnName)
@@ -116,9 +120,9 @@ class ResultSetMapping
 
     public function addScalarResult($columnName, $alias)
     {
-        $this->_scalarMappings[$columnName] = $alias;
-        if ( ! $this->_isMixed && $this->_fieldMappings) {
-            $this->_isMixed = true;
+        $this->scalarMappings[$columnName] = $alias;
+        if ( ! $this->isMixed && $this->fieldMappings) {
+            $this->isMixed = true;
         }
     }    
 
@@ -127,7 +131,7 @@ class ResultSetMapping
      */
     public function isScalarResult($columnName)
     {
-        return isset($this->_scalarMappings[$columnName]);
+        return isset($this->scalarMappings[$columnName]);
     }
 
     /**
@@ -136,7 +140,7 @@ class ResultSetMapping
      */
     public function getClass($alias)
     {
-        return $this->_aliasMap[$alias];
+        return $this->aliasMap[$alias];
     }
 
     /**
@@ -147,7 +151,7 @@ class ResultSetMapping
      */
     public function getScalarAlias($columnName)
     {
-        return $this->_scalarMappings[$columnName];
+        return $this->scalarMappings[$columnName];
     }
 
     /**
@@ -157,17 +161,17 @@ class ResultSetMapping
      */
     public function getOwningClass($columnName)
     {
-        return $this->_aliasMap[$this->_columnOwnerMap[$columnName]];
+        return $this->aliasMap[$this->columnOwnerMap[$columnName]];
     }
 
     public function getRelation($alias)
     {
-        return $this->_relationMap[$alias];
+        return $this->relationMap[$alias];
     }
 
     public function isRelation($alias)
     {
-        return isset($this->_relationMap[$alias]);
+        return isset($this->relationMap[$alias]);
     }
 
     /**
@@ -177,7 +181,7 @@ class ResultSetMapping
      */
     public function getEntityAlias($columnName)
     {
-        return $this->_columnOwnerMap[$columnName];
+        return $this->columnOwnerMap[$columnName];
     }
 
     /**
@@ -187,12 +191,12 @@ class ResultSetMapping
      */
     public function getParentAlias($alias)
     {
-        return $this->_parentAliasMap[$alias];
+        return $this->parentAliasMap[$alias];
     }
 
     public function hasParentAlias($alias)
     {
-        return isset($this->_parentAliasMap[$alias]);
+        return isset($this->parentAliasMap[$alias]);
     }
 
     /**
@@ -203,32 +207,32 @@ class ResultSetMapping
      */
     public function getFieldName($columnName)
     {
-        return $this->_fieldMappings[$columnName];
+        return $this->fieldMappings[$columnName];
     }
 
     public function getAliasMap()
     {
-        return $this->_aliasMap;
+        return $this->aliasMap;
     }
 
     public function getEntityResultCount()
     {
-        return count($this->_aliasMap);
+        return count($this->aliasMap);
     }
 
     public function isMixedResult()
     {
-        return $this->_isMixed;
+        return $this->isMixed;
     }
 
     public function addIgnoredColumn($columnName)
     {
-        $this->_ignoredColumns[$columnName] = true;
+        $this->ignoredColumns[$columnName] = true;
     }
 
     public function isIgnoredColumn($columnName)
     {
-        return isset($this->_ignoredColumns[$columnName]);
+        return isset($this->ignoredColumns[$columnName]);
     }
 }
 
diff --git a/tests/Doctrine/Tests/ORM/Hydration/ObjectHydratorTest.php b/tests/Doctrine/Tests/ORM/Hydration/ObjectHydratorTest.php
index f0598c00d..be5976164 100644
--- a/tests/Doctrine/Tests/ORM/Hydration/ObjectHydratorTest.php
+++ b/tests/Doctrine/Tests/ORM/Hydration/ObjectHydratorTest.php
@@ -679,76 +679,4 @@ class ObjectHydratorTest extends HydrationTest
             ++$rowNum;
         }
     }
-
-    /**
-     * select u.id, u.status, p.phonenumber, upper(u.name) nameUpper from User u
-     * join u.phonenumbers p
-     * =
-     * select u.id, u.status, p.phonenumber, upper(u.name) as u__0 from USERS u
-     * INNER JOIN PHONENUMBERS p ON u.id = p.user_id
-     *
-     * @dataProvider hydrationModeProvider
-     */
-    public function testNewHydrationMixedQueryFetchJoinPerformance()
-    {
-        $rsm = new ResultSetMapping;
-        $rsm->addEntityResult($this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'), 'u');
-        /*$rsm->addJoinedEntityResult(
-                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsPhonenumber'),
-                'p',
-                'u',
-                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser')->getAssociationMapping('phonenumbers')
-        );*/
-        $rsm->addFieldResult('u', 'u__id', 'id');
-        $rsm->addFieldResult('u', 'u__status', 'status');
-        $rsm->addFieldResult('u', 'u__username', 'username');
-        $rsm->addFieldResult('u', 'u__name', 'name');
-        //$rsm->addScalarResult('sclr0', 'nameUpper');
-        //$rsm->addFieldResult('p', 'p__phonenumber', 'phonenumber');
-
-        // Faked result set
-        $resultSet = array(
-            //row1
-            array(
-                'u__id' => '1',
-                'u__status' => 'developer',
-                'u__username' => 'romanb',
-                'u__name' => 'Roman',
-                //'sclr0' => 'ROMANB',
-                //'p__phonenumber' => '42',
-            ),
-            array(
-                'u__id' => '1',
-                'u__status' => 'developer',
-                'u__username' => 'romanb',
-                'u__name' => 'Roman',
-                //'sclr0' => 'ROMANB',
-                //'p__phonenumber' => '43',
-            ),
-            array(
-                'u__id' => '2',
-                'u__status' => 'developer',
-                'u__username' => 'romanb',
-                'u__name' => 'Roman',
-                //'sclr0' => 'JWAGE',
-                //'p__phonenumber' => '91'
-            )
-        );
-
-        for ($i = 4; $i < 10000; ++$i) {
-            $resultSet[] = array(
-                'u__id' => $i,
-                'u__status' => 'developer',
-                'u__username' => 'jwage',
-                'u__name' => 'Jonathan',
-                //'sclr0' => 'JWAGE' . $i,
-                //'p__phonenumber' => '91'
-            );
-        }
-
-        $stmt = new HydratorMockStatement($resultSet);
-        $hydrator = new \Doctrine\ORM\Internal\Hydration\ObjectHydrator($this->_em);
-
-        $result = $hydrator->hydrateAll($stmt, $rsm);
-    }
 }
\ No newline at end of file
diff --git a/tests/Doctrine/Tests/ORM/Performance/AllTests.php b/tests/Doctrine/Tests/ORM/Performance/AllTests.php
new file mode 100644
index 000000000..5acea3e0e
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Performance/AllTests.php
@@ -0,0 +1,31 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Performance;
+
+if (!defined('PHPUnit_MAIN_METHOD')) {
+    define('PHPUnit_MAIN_METHOD', 'Orm_Performance_AllTests::main');
+}
+
+require_once __DIR__ . '/../../TestInit.php';
+
+
+class AllTests
+{
+    public static function main()
+    {
+        \PHPUnit_TextUI_TestRunner::run(self::suite());
+    }
+
+    public static function suite()
+    {
+        $suite = new \Doctrine\Tests\DoctrineTestSuite('Doctrine Orm Performance');
+
+        $suite->addTestSuite('Doctrine\Tests\ORM\Performance\HydrationPerformanceTest');
+
+        return $suite;
+    }
+}
+
+if (PHPUnit_MAIN_METHOD == 'Orm_Performance_AllTests::main') {
+    AllTests::main();
+}
\ No newline at end of file
diff --git a/tests/Doctrine/Tests/ORM/Performance/HydrationPerformanceTest.php b/tests/Doctrine/Tests/ORM/Performance/HydrationPerformanceTest.php
new file mode 100644
index 000000000..8bd60fdcf
--- /dev/null
+++ b/tests/Doctrine/Tests/ORM/Performance/HydrationPerformanceTest.php
@@ -0,0 +1,268 @@
+<?php
+
+namespace Doctrine\Tests\ORM\Performance;
+
+require_once __DIR__ . '/../../TestInit.php';
+
+use Doctrine\Tests\Mocks\HydratorMockStatement;
+use Doctrine\ORM\Query\ResultSetMapping;
+
+/**
+ * Tests to prevent serious performance regressions.
+ *
+ * IMPORTANT: Be sure to run these tests withoug xdebug or similar tools that
+ * seriously degrade performance.
+ *
+ * @author robo
+ */
+class HydrationPerformanceTest extends \Doctrine\Tests\OrmPerformanceTestCase
+{
+    /**
+     * Times for comparison:
+     *
+     * [romanb: 10000 rows => 1.8 seconds]
+     *
+     * MAXIMUM TIME: 3 seconds
+     */
+    public function testNewHydrationSimpleQueryArrayHydrationPerformance()
+    {
+        $rsm = new ResultSetMapping;
+        $rsm->addEntityResult($this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'), 'u');
+        $rsm->addFieldResult('u', 'u__id', 'id');
+        $rsm->addFieldResult('u', 'u__status', 'status');
+        $rsm->addFieldResult('u', 'u__username', 'username');
+        $rsm->addFieldResult('u', 'u__name', 'name');
+
+        // Faked result set
+        $resultSet = array(
+            //row1
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+            ),
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+            ),
+            array(
+                'u__id' => '2',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+            )
+        );
+
+        for ($i = 4; $i < 10000; ++$i) {
+            $resultSet[] = array(
+                'u__id' => $i,
+                'u__status' => 'developer',
+                'u__username' => 'jwage',
+                'u__name' => 'Jonathan',
+            );
+        }
+
+        $stmt = new HydratorMockStatement($resultSet);
+        $hydrator = new \Doctrine\ORM\Internal\Hydration\ArrayHydrator($this->_em);
+
+        $this->setMaxRunningTime(3);
+        $result = $hydrator->hydrateAll($stmt, $rsm);
+    }
+
+    /**
+     * Times for comparison:
+     *
+     * [romanb: 10000 rows => 3.0 seconds]
+     *
+     * MAXIMUM TIME: 4 seconds
+     */
+    public function testNewHydrationMixedQueryFetchJoinArrayHydrationPerformance()
+    {
+        $rsm = new ResultSetMapping;
+        $rsm->addEntityResult($this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'), 'u');
+        $rsm->addJoinedEntityResult(
+                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsPhonenumber'),
+                'p',
+                'u',
+                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser')->getAssociationMapping('phonenumbers')
+        );
+        $rsm->addFieldResult('u', 'u__id', 'id');
+        $rsm->addFieldResult('u', 'u__status', 'status');
+        $rsm->addFieldResult('u', 'u__username', 'username');
+        $rsm->addFieldResult('u', 'u__name', 'name');
+        $rsm->addScalarResult('sclr0', 'nameUpper');
+        $rsm->addFieldResult('p', 'p__phonenumber', 'phonenumber');
+
+        // Faked result set
+        $resultSet = array(
+            //row1
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+                'sclr0' => 'ROMANB',
+                'p__phonenumber' => '42',
+            ),
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+                'sclr0' => 'ROMANB',
+                'p__phonenumber' => '43',
+            ),
+            array(
+                'u__id' => '2',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+                'sclr0' => 'JWAGE',
+                'p__phonenumber' => '91'
+            )
+        );
+
+        for ($i = 4; $i < 10000; ++$i) {
+            $resultSet[] = array(
+                'u__id' => $i,
+                'u__status' => 'developer',
+                'u__username' => 'jwage',
+                'u__name' => 'Jonathan',
+                'sclr0' => 'JWAGE' . $i,
+                'p__phonenumber' => '91'
+            );
+        }
+
+        $stmt = new HydratorMockStatement($resultSet);
+        $hydrator = new \Doctrine\ORM\Internal\Hydration\ArrayHydrator($this->_em);
+
+        $this->setMaxRunningTime(4);
+        $result = $hydrator->hydrateAll($stmt, $rsm);
+    }
+
+    /**
+     * [romanb: 10000 rows => 3.4 seconds]
+     *
+     * MAXIMUM TIME: 4 seconds
+     */
+    public function testSimpleQueryObjectHydrationPerformance()
+    {
+        $rsm = new ResultSetMapping;
+        $rsm->addEntityResult($this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'), 'u');
+        $rsm->addFieldResult('u', 'u__id', 'id');
+        $rsm->addFieldResult('u', 'u__status', 'status');
+        $rsm->addFieldResult('u', 'u__username', 'username');
+        $rsm->addFieldResult('u', 'u__name', 'name');
+
+        // Faked result set
+        $resultSet = array(
+            //row1
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+            ),
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+            ),
+            array(
+                'u__id' => '2',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+            )
+        );
+
+        for ($i = 4; $i < 10000; ++$i) {
+            $resultSet[] = array(
+                'u__id' => $i,
+                'u__status' => 'developer',
+                'u__username' => 'jwage',
+                'u__name' => 'Jonathan',
+            );
+        }
+
+        $stmt = new HydratorMockStatement($resultSet);
+        $hydrator = new \Doctrine\ORM\Internal\Hydration\ObjectHydrator($this->_em);
+
+        $this->setMaxRunningTime(4);
+        $result = $hydrator->hydrateAll($stmt, $rsm);
+    }
+
+    /**
+     * [romanb: 2000 rows => 3.1 seconds]
+     *
+     * MAXIMUM TIME: 4 seconds
+     */
+    public function testMixedQueryFetchJoinObjectHydrationPerformance()
+    {
+        $rsm = new ResultSetMapping;
+        $rsm->addEntityResult($this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser'), 'u');
+        $rsm->addJoinedEntityResult(
+                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsPhonenumber'),
+                'p',
+                'u',
+                $this->_em->getClassMetadata('Doctrine\Tests\Models\CMS\CmsUser')->getAssociationMapping('phonenumbers')
+        );
+        $rsm->addFieldResult('u', 'u__id', 'id');
+        $rsm->addFieldResult('u', 'u__status', 'status');
+        $rsm->addFieldResult('u', 'u__username', 'username');
+        $rsm->addFieldResult('u', 'u__name', 'name');
+        $rsm->addScalarResult('sclr0', 'nameUpper');
+        $rsm->addFieldResult('p', 'p__phonenumber', 'phonenumber');
+
+        // Faked result set
+        $resultSet = array(
+            //row1
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+                'sclr0' => 'ROMANB',
+                'p__phonenumber' => '42',
+            ),
+            array(
+                'u__id' => '1',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+                'sclr0' => 'ROMANB',
+                'p__phonenumber' => '43',
+            ),
+            array(
+                'u__id' => '2',
+                'u__status' => 'developer',
+                'u__username' => 'romanb',
+                'u__name' => 'Roman',
+                'sclr0' => 'JWAGE',
+                'p__phonenumber' => '91'
+            )
+        );
+
+        for ($i = 4; $i < 2000; ++$i) {
+            $resultSet[] = array(
+                'u__id' => $i,
+                'u__status' => 'developer',
+                'u__username' => 'jwage',
+                'u__name' => 'Jonathan',
+                'sclr0' => 'JWAGE' . $i,
+                'p__phonenumber' => '91'
+            );
+        }
+
+        $stmt = new HydratorMockStatement($resultSet);
+        $hydrator = new \Doctrine\ORM\Internal\Hydration\ObjectHydrator($this->_em);
+
+        $this->setMaxRunningTime(4);
+        $result = $hydrator->hydrateAll($stmt, $rsm);
+    }
+}
+
diff --git a/tests/Doctrine/Tests/OrmPerformanceTestCase.php b/tests/Doctrine/Tests/OrmPerformanceTestCase.php
new file mode 100644
index 000000000..5350e211f
--- /dev/null
+++ b/tests/Doctrine/Tests/OrmPerformanceTestCase.php
@@ -0,0 +1,68 @@
+<?php
+
+namespace Doctrine\Tests;
+
+/**
+ * Description of DoctrinePerformanceTestCase
+ *
+ * @author robo
+ */
+class OrmPerformanceTestCase extends OrmTestCase
+{
+    protected $_em;
+
+    protected function setUp()
+    {
+        parent::setUp();
+        $this->_em = $this->_getTestEntityManager();
+    }
+
+    /**
+     * @var    integer
+     */
+    protected $maxRunningTime = 0;
+
+    /**
+     */
+    protected function runTest()
+    {
+        $s = microtime(true);
+        parent::runTest();
+        $time = microtime(true) - $s;
+
+        if ($this->maxRunningTime != 0 && $time > $this->maxRunningTime) {
+            $this->fail(
+              sprintf(
+                'expected running time: <= %s but was: %s',
+
+                $this->maxRunningTime,
+                $time
+              )
+            );
+        }
+    }
+
+    /**
+     * @param  integer $maxRunningTime
+     * @throws InvalidArgumentException
+     * @since  Method available since Release 2.3.0
+     */
+    public function setMaxRunningTime($maxRunningTime)
+    {
+        if (is_integer($maxRunningTime) && $maxRunningTime >= 0) {
+            $this->maxRunningTime = $maxRunningTime;
+        } else {
+            throw new \InvalidArgumentException;
+        }
+    }
+
+    /**
+     * @return integer
+     * @since  Method available since Release 2.3.0
+     */
+    public function getMaxRunningTime()
+    {
+        return $this->maxRunningTime;
+    }
+}
+