diff --git a/resources/sql/autopatches/20170915.ref.02.drop.id.sql b/resources/sql/autopatches/20170915.ref.02.drop.id.sql
new file mode 100644
index 0000000000..177fde3b6a
--- /dev/null
+++ b/resources/sql/autopatches/20170915.ref.02.drop.id.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_repository.repository_refcursor
+  DROP COLUMN commitIdentifier;
diff --git a/resources/sql/autopatches/20170915.ref.03.drop.closed.sql b/resources/sql/autopatches/20170915.ref.03.drop.closed.sql
new file mode 100644
index 0000000000..927ee04b65
--- /dev/null
+++ b/resources/sql/autopatches/20170915.ref.03.drop.closed.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_repository.repository_refcursor
+  DROP COLUMN isClosed;
diff --git a/resources/sql/autopatches/20170915.ref.04.uniq.sql b/resources/sql/autopatches/20170915.ref.04.uniq.sql
new file mode 100644
index 0000000000..0bef69fc4a
--- /dev/null
+++ b/resources/sql/autopatches/20170915.ref.04.uniq.sql
@@ -0,0 +1,2 @@
+ALTER TABLE {$NAMESPACE}_repository.repository_refcursor
+  ADD UNIQUE KEY `key_ref` (repositoryPHID, refType, refNameHash);
diff --git a/src/applications/repository/storage/PhabricatorRepositoryRefCursor.php b/src/applications/repository/storage/PhabricatorRepositoryRefCursor.php
index febbed3ee6..ec0c90744c 100644
--- a/src/applications/repository/storage/PhabricatorRepositoryRefCursor.php
+++ b/src/applications/repository/storage/PhabricatorRepositoryRefCursor.php
@@ -1,99 +1,96 @@
 <?php
 
 /**
  * Stores the previous value of a ref (like a branch or tag) so we can figure
  * out how a repository has changed when we discover new commits or branch
  * heads.
  */
 final class PhabricatorRepositoryRefCursor
   extends PhabricatorRepositoryDAO
   implements PhabricatorPolicyInterface {
 
   const TYPE_BRANCH = 'branch';
   const TYPE_TAG = 'tag';
   const TYPE_BOOKMARK = 'bookmark';
   const TYPE_REF = 'ref';
 
   protected $repositoryPHID;
   protected $refType;
   protected $refNameHash;
   protected $refNameRaw;
   protected $refNameEncoding;
-  protected $commitIdentifier;
-  protected $isClosed = 0;
 
   private $repository = self::ATTACHABLE;
 
   protected function getConfiguration() {
     return array(
       self::CONFIG_TIMESTAMPS => false,
       self::CONFIG_AUX_PHID => true,
       self::CONFIG_BINARY => array(
         'refNameRaw' => true,
       ),
       self::CONFIG_COLUMN_SCHEMA => array(
         'refType' => 'text32',
         'refNameHash' => 'bytes12',
-        'commitIdentifier' => 'text40',
         'refNameEncoding' => 'text16?',
-        'isClosed' => 'bool',
       ),
       self::CONFIG_KEY_SCHEMA => array(
-        'key_cursor' => array(
+        'key_ref' => array(
           'columns' => array('repositoryPHID', 'refType', 'refNameHash'),
+          'unique' => true,
         ),
       ),
     ) + parent::getConfiguration();
   }
 
   public function generatePHID() {
     return PhabricatorPHID::generateNewPHID(
       PhabricatorRepositoryRefCursorPHIDType::TYPECONST);
   }
 
   public function getRefName() {
     return $this->getUTF8StringFromStorage(
       $this->getRefNameRaw(),
       $this->getRefNameEncoding());
   }
 
   public function setRefName($ref_raw) {
     $this->setRefNameRaw($ref_raw);
     $this->setRefNameHash(PhabricatorHash::digestForIndex($ref_raw));
     $this->setRefNameEncoding($this->detectEncodingForStorage($ref_raw));
 
     return $this;
   }
 
   public function attachRepository(PhabricatorRepository $repository) {
     $this->repository = $repository;
     return $this;
   }
 
   public function getRepository() {
     return $this->assertAttached($this->repository);
   }
 
 
 /* -(  PhabricatorPolicyInterface  )----------------------------------------- */
 
 
   public function getCapabilities() {
     return array(
       PhabricatorPolicyCapability::CAN_VIEW,
     );
   }
 
   public function getPolicy($capability) {
     return $this->getRepository()->getPolicy($capability);
   }
 
   public function hasAutomaticCapability($capability, PhabricatorUser $viewer) {
     return $this->getRepository()->hasAutomaticCapability($capability, $viewer);
   }
 
   public function describeAutomaticCapability($capability) {
     return pht('Repository refs have the same policies as their repository.');
   }
 
 }