Drupal 8.0.0 beta 12. More info: https://www.drupal.org/node/2514176

core/modules/file/src/FileStorageSchema.php

@@ -0,0 +1,41 @@
+<?php
+
+/**
+ * @file
+ * Contains \Drupal\file\FileStorageSchema.
+ */
+
+namespace Drupal\file;
+
+use Drupal\Core\Entity\Sql\SqlContentEntityStorageSchema;
+use Drupal\Core\Field\FieldStorageDefinitionInterface;
+
+/**
+ * Defines the file schema handler.
+ */
+class FileStorageSchema extends SqlContentEntityStorageSchema {
+
+  /**
+   * {@inheritdoc}
+   */
+  protected function getSharedTableFieldSchema(FieldStorageDefinitionInterface $storage_definition, $table_name, array $column_mapping) {
+    $schema = parent::getSharedTableFieldSchema($storage_definition, $table_name, $column_mapping);
+    $field_name = $storage_definition->getName();
+
+    if ($table_name == 'file_managed') {
+      switch ($field_name) {
+        case 'status':
+        case 'changed':
+          $this->addSharedTableFieldIndex($storage_definition, $schema, TRUE);
+          break;
+
+        case 'uri':
+          $this->addSharedTableFieldIndex($storage_definition, $schema, TRUE);
+          break;
+      }
+    }
+
+    return $schema;
+  }
+
+}