diff --git a/core/includes/database.inc b/core/includes/database.inc
index 92d4119f70d..216c88e51d8 100644
--- a/core/includes/database.inc
+++ b/core/includes/database.inc
@@ -29,10 +29,10 @@ use Drupal\Core\Database\Query\Condition;
  * inherits much of its syntax and semantics.
  *
  * Most Drupal database SELECT queries are performed by a call to db_query() or
- * db_query_range(). Module authors should also consider using the PagerDefault
- * Extender for queries that return results that need to be presented on
- * multiple pages, and the Tablesort Extender for generating appropriate queries
- * for sortable tables.
+ * db_query_range(). Module authors should also consider using the
+ * Drupal\Core\Database\Query\PagerSelectExtender for queries that return
+ * results that need to be presented on multiple pages, and the Tablesort
+ * Extender for generating appropriate queries for sortable tables.
  *
  * For example, one might wish to return a list of the most recent 10 nodes
  * authored by a given user. Instead of directly issuing the SQL query
diff --git a/core/includes/pager.inc b/core/includes/pager.inc
index 9419cededb2..40d9c01078f 100644
--- a/core/includes/pager.inc
+++ b/core/includes/pager.inc
@@ -1,174 +1,10 @@
 <?php
 
-use Drupal\Core\Database\Connection;
-use Drupal\Core\Database\Query\SelectExtender;
-use Drupal\Core\Database\Query\SelectInterface;
-
 /**
  * @file
  * Functions to aid in presenting database results as a set of pages.
  */
 
-/**
- * Query extender for pager queries.
- *
- * This is the "default" pager mechanism.  It creates a paged query with a fixed
- * number of entries per page.
- */
-class PagerDefault extends SelectExtender {
-
-  /**
-   * The highest element we've autogenerated so far.
-   *
-   * @var int
-   */
-  static $maxElement = 0;
-
-  /**
-   * The number of elements per page to allow.
-   *
-   * @var int
-   */
-  protected $limit = 10;
-
-  /**
-   * The unique ID of this pager on this page.
-   *
-   * @var int
-   */
-  protected $element = NULL;
-
-  /**
-   * The count query that will be used for this pager.
-   *
-   * @var SelectQueryInterface
-   */
-  protected $customCountQuery = FALSE;
-
-  public function __construct(SelectInterface $query, Connection $connection) {
-    parent::__construct($query, $connection);
-
-    // Add pager tag. Do this here to ensure that it is always added before
-    // preExecute() is called.
-    $this->addTag('pager');
-  }
-
-  /**
-   * Override the execute method.
-   *
-   * Before we run the query, we need to add pager-based range() instructions
-   * to it.
-   */
-  public function execute() {
-
-    // Add convenience tag to mark that this is an extended query. We have to
-    // do this in the constructor to ensure that it is set before preExecute()
-    // gets called.
-    if (!$this->preExecute($this)) {
-      return NULL;
-    }
-
-    // A NULL limit is the "kill switch" for pager queries.
-    if (empty($this->limit)) {
-      return;
-    }
-    $this->ensureElement();
-
-    $total_items = $this->getCountQuery()->execute()->fetchField();
-    $current_page = pager_default_initialize($total_items, $this->limit, $this->element);
-    $this->range($current_page * $this->limit, $this->limit);
-
-    // Now that we've added our pager-based range instructions, run the query normally.
-    return $this->query->execute();
-  }
-
-  /**
-   * Ensure that there is an element associated with this query.
-   * If an element was not specified previously, then the value of the
-   * $maxElement counter is taken, after which the counter is incremented.
-   *
-   * After running this method, access $this->element to get the element for this
-   * query.
-   */
-  protected function ensureElement() {
-    if (!isset($this->element)) {
-      $this->element = self::$maxElement++;
-    }
-  }
-
-  /**
-   * Specify the count query object to use for this pager.
-   *
-   * You will rarely need to specify a count query directly.  If not specified,
-   * one is generated off of the pager query itself.
-   *
-   * @param SelectQueryInterface $query
-   *   The count query object.  It must return a single row with a single column,
-   *   which is the total number of records.
-   */
-  public function setCountQuery(SelectInterface $query) {
-    $this->customCountQuery = $query;
-  }
-
-  /**
-   * Retrieve the count query for this pager.
-   *
-   * The count query may be specified manually or, by default, taken from the
-   * query we are extending.
-   *
-   * @return SelectQueryInterface
-   *   A count query object.
-   */
-  public function getCountQuery() {
-    if ($this->customCountQuery) {
-      return $this->customCountQuery;
-    }
-    else {
-      return $this->query->countQuery();
-    }
-  }
-
-  /**
-   * Specify the maximum number of elements per page for this query.
-   *
-   * The default if not specified is 10 items per page.
-   *
-   * @param $limit
-   *   An integer specifying the number of elements per page.  If passed a false
-   *   value (FALSE, 0, NULL), the pager is disabled.
-   */
-  public function limit($limit = 10) {
-    $this->limit = $limit;
-    return $this;
-  }
-
-  /**
-   * Specify the element ID for this pager query.
-   *
-   * The element is used to differentiate different pager queries on the same
-   * page so that they may be operated independently.  If you do not specify an
-   * element, every pager query on the page will get a unique element.  If for
-   * whatever reason you want to explicitly define an element for a given query,
-   * you may do so here.
-   *
-   * Setting the element here also increments the static $maxElement counter,
-   * which is used for determining the $element when there's none specified.
-   *
-   * Note that no collision detection is done when setting an element ID
-   * explicitly, so it is possible for two pagers to end up using the same ID
-   * if both are set explicitly.
-   *
-   * @param $element
-   */
-  public function element($element) {
-    $this->element = $element;
-    if ($element >= self::$maxElement) {
-      self::$maxElement = $element + 1;
-    }
-    return $this;
-  }
-}
-
 /**
  * Returns the current page being requested for display within a pager.
  *
@@ -206,10 +42,11 @@ function pager_find_page($element = 0) {
  * If the items being displayed result from a database query performed using
  * Drupal's database API, and if you have control over the construction of the
  * database query, you do not need to call this function directly; instead, you
- * can simply extend the query object with the 'PagerDefault' extender before
- * executing it. For example:
+ * can simply extend the query object with the 'PagerSelectExtender' extender
+ * before executing it. For example:
  * @code
- *   $query = db_select('some_table')->extend('PagerDefault');
+ *   $query = db_select('some_table')
+ *     ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
  * @endcode
  *
  * However, if you are using a different method for generating the items to be
diff --git a/core/lib/Drupal/Core/Database/Query/ExtendableInterface.php b/core/lib/Drupal/Core/Database/Query/ExtendableInterface.php
index 1ebac45ac19..01dcc90f867 100644
--- a/core/lib/Drupal/Core/Database/Query/ExtendableInterface.php
+++ b/core/lib/Drupal/Core/Database/Query/ExtendableInterface.php
@@ -25,8 +25,7 @@ interface ExtendableInterface {
    * @param $extender_name
    *   The base name of the extending class.  The base name will be checked
    *   against the current database connection to allow driver-specific subclasses
-   *   as well, using the same logic as the query objects themselves.  For example,
-   *   PagerDefault_mysql is the MySQL-specific override for PagerDefault.
+   *   as well, using the same logic as the query objects themselves.
    * @return Drupal\Core\Database\Query\ExtendableInterface
    *   The extender object, which now contains a reference to this object.
    */
diff --git a/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php b/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php
new file mode 100644
index 00000000000..0668fa5cf91
--- /dev/null
+++ b/core/lib/Drupal/Core/Database/Query/PagerSelectExtender.php
@@ -0,0 +1,172 @@
+<?php
+
+/**
+ * @file
+ * Definition of Drupal\Core\Database\Query\PagerSelectExtender
+ */
+
+namespace Drupal\Core\Database\Query;
+
+use Drupal\Core\Database\Connection;
+use Drupal\Core\Database\Query\SelectExtender;
+use Drupal\Core\Database\Query\SelectInterface;
+
+/**
+ * Query extender for pager queries.
+ *
+ * This is the "default" pager mechanism.  It creates a paged query with a fixed
+ * number of entries per page.
+ */
+class PagerSelectExtender extends SelectExtender {
+
+  /**
+   * The highest element we've autogenerated so far.
+   *
+   * @var int
+   */
+  static $maxElement = 0;
+
+  /**
+   * The number of elements per page to allow.
+   *
+   * @var int
+   */
+  protected $limit = 10;
+
+  /**
+   * The unique ID of this pager on this page.
+   *
+   * @var int
+   */
+  protected $element = NULL;
+
+  /**
+   * The count query that will be used for this pager.
+   *
+   * @var SelectQueryInterface
+   */
+  protected $customCountQuery = FALSE;
+
+  public function __construct(SelectInterface $query, Connection $connection) {
+    parent::__construct($query, $connection);
+
+    // Add pager tag. Do this here to ensure that it is always added before
+    // preExecute() is called.
+    $this->addTag('pager');
+  }
+
+  /**
+   * Override the execute method.
+   *
+   * Before we run the query, we need to add pager-based range() instructions
+   * to it.
+   */
+  public function execute() {
+
+    // Add convenience tag to mark that this is an extended query. We have to
+    // do this in the constructor to ensure that it is set before preExecute()
+    // gets called.
+    if (!$this->preExecute($this)) {
+      return NULL;
+    }
+
+    // A NULL limit is the "kill switch" for pager queries.
+    if (empty($this->limit)) {
+      return;
+    }
+    $this->ensureElement();
+
+    $total_items = $this->getCountQuery()->execute()->fetchField();
+    $current_page = pager_default_initialize($total_items, $this->limit, $this->element);
+    $this->range($current_page * $this->limit, $this->limit);
+
+    // Now that we've added our pager-based range instructions, run the query normally.
+    return $this->query->execute();
+  }
+
+  /**
+   * Ensure that there is an element associated with this query.
+   * If an element was not specified previously, then the value of the
+   * $maxElement counter is taken, after which the counter is incremented.
+   *
+   * After running this method, access $this->element to get the element for this
+   * query.
+   */
+  protected function ensureElement() {
+    if (!isset($this->element)) {
+      $this->element = self::$maxElement++;
+    }
+  }
+
+  /**
+   * Specify the count query object to use for this pager.
+   *
+   * You will rarely need to specify a count query directly.  If not specified,
+   * one is generated off of the pager query itself.
+   *
+   * @param SelectQueryInterface $query
+   *   The count query object.  It must return a single row with a single column,
+   *   which is the total number of records.
+   */
+  public function setCountQuery(SelectInterface $query) {
+    $this->customCountQuery = $query;
+  }
+
+  /**
+   * Retrieve the count query for this pager.
+   *
+   * The count query may be specified manually or, by default, taken from the
+   * query we are extending.
+   *
+   * @return SelectQueryInterface
+   *   A count query object.
+   */
+  public function getCountQuery() {
+    if ($this->customCountQuery) {
+      return $this->customCountQuery;
+    }
+    else {
+      return $this->query->countQuery();
+    }
+  }
+
+  /**
+   * Specify the maximum number of elements per page for this query.
+   *
+   * The default if not specified is 10 items per page.
+   *
+   * @param $limit
+   *   An integer specifying the number of elements per page.  If passed a false
+   *   value (FALSE, 0, NULL), the pager is disabled.
+   */
+  public function limit($limit = 10) {
+    $this->limit = $limit;
+    return $this;
+  }
+
+  /**
+   * Specify the element ID for this pager query.
+   *
+   * The element is used to differentiate different pager queries on the same
+   * page so that they may be operated independently.  If you do not specify an
+   * element, every pager query on the page will get a unique element.  If for
+   * whatever reason you want to explicitly define an element for a given query,
+   * you may do so here.
+   *
+   * Setting the element here also increments the static $maxElement counter,
+   * which is used for determining the $element when there's none specified.
+   *
+   * Note that no collision detection is done when setting an element ID
+   * explicitly, so it is possible for two pagers to end up using the same ID
+   * if both are set explicitly.
+   *
+   * @param $element
+   */
+  public function element($element) {
+    $this->element = $element;
+    if ($element >= self::$maxElement) {
+      self::$maxElement = $element + 1;
+    }
+    return $this;
+  }
+}
diff --git a/core/modules/aggregator/aggregator.pages.inc b/core/modules/aggregator/aggregator.pages.inc
index 7f820770fed..fcc61b00236 100644
--- a/core/modules/aggregator/aggregator.pages.inc
+++ b/core/modules/aggregator/aggregator.pages.inc
@@ -134,7 +134,7 @@ function aggregator_load_feed_items($type, $data = NULL) {
   }
 
   $result = $query
-    ->extend('PagerDefault')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
     ->limit(20)
     ->orderBy('i.timestamp', 'DESC')
     ->orderBy('i.iid', 'DESC')
diff --git a/core/modules/comment/comment.admin.inc b/core/modules/comment/comment.admin.inc
index 4329492a565..3a853df6a81 100644
--- a/core/modules/comment/comment.admin.inc
+++ b/core/modules/comment/comment.admin.inc
@@ -79,7 +79,9 @@ function comment_admin_overview($form, &$form_state, $arg) {
     'operations' => array('data' => t('Operations')),
   );
 
-  $query = db_select('comment', 'c')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('comment', 'c')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->join('node', 'n', 'n.nid = c.nid');
   $query->addField('n', 'title', 'node_title');
   $query->addTag('node_access');
diff --git a/core/modules/comment/comment.module b/core/modules/comment/comment.module
index 4fa8fee71d6..5684731cb19 100644
--- a/core/modules/comment/comment.module
+++ b/core/modules/comment/comment.module
@@ -849,7 +849,8 @@ function comment_node_page_additions(Node $node) {
  * to consider the trailing "/" so we use a substring only.
  */
 function comment_get_thread(Node $node, $mode, $comments_per_page) {
-  $query = db_select('comment', 'c')->extend('PagerDefault');
+  $query = db_select('comment', 'c')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
   $query->addField('c', 'cid');
   $query
     ->condition('c.nid', $node->nid)
diff --git a/core/modules/dblog/dblog.admin.inc b/core/modules/dblog/dblog.admin.inc
index b2da7eddf2d..dafc91b021c 100644
--- a/core/modules/dblog/dblog.admin.inc
+++ b/core/modules/dblog/dblog.admin.inc
@@ -37,7 +37,9 @@ function dblog_overview() {
     array('data' => t('Operations')),
   );
 
-  $query = db_select('watchdog', 'w')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('watchdog', 'w')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->leftJoin('users', 'u', 'w.uid = u.uid');
   $query
     ->fields('w', array('wid', 'uid', 'severity', 'type', 'timestamp', 'message', 'variables', 'link'))
@@ -96,7 +98,9 @@ function dblog_top($type) {
   $count_query->addExpression('COUNT(DISTINCT(message))');
   $count_query->condition('type', $type);
 
-  $query = db_select('watchdog', 'w')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('watchdog', 'w')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->addExpression('COUNT(wid)', 'count');
   $query = $query
     ->fields('w', array('message', 'variables'))
diff --git a/core/modules/entity/lib/Drupal/entity/EntityFieldQuery.php b/core/modules/entity/lib/Drupal/entity/EntityFieldQuery.php
index 852dced4176..05f338b6c68 100644
--- a/core/modules/entity/lib/Drupal/entity/EntityFieldQuery.php
+++ b/core/modules/entity/lib/Drupal/entity/EntityFieldQuery.php
@@ -9,7 +9,7 @@ namespace Drupal\entity;
 
 use Drupal\entity\EntityFieldQueryException;
 use Drupal\Core\Database\Query\Select;
-use PagerDefault;
+use Drupal\Core\Database\Query\PagerSelectExtender;
 
 /**
  * Retrieves entities matching a given set of conditions.
@@ -571,10 +571,10 @@ class EntityFieldQuery {
    */
   public function pager($limit = 10, $element = NULL) {
     if (!isset($element)) {
-      $element = PagerDefault::$maxElement++;
+      $element = PagerSelectExtender::$maxElement++;
     }
-    elseif ($element >= PagerDefault::$maxElement) {
-      PagerDefault::$maxElement = $element + 1;
+    elseif ($element >= PagerSelectExtender::$maxElement) {
+      PagerSelectExtender::$maxElement = $element + 1;
     }
 
     $this->pager = array(
diff --git a/core/modules/forum/forum.module b/core/modules/forum/forum.module
index 28e7f1786cb..25a4369363a 100644
--- a/core/modules/forum/forum.module
+++ b/core/modules/forum/forum.module
@@ -893,7 +893,9 @@ function forum_get_topics($tid, $sortby, $forum_per_page) {
     }
   }
 
-  $query = db_select('forum_index', 'f')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('forum_index', 'f')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->fields('f');
   $query
     ->condition('f.tid', $tid)
diff --git a/core/modules/locale/locale.pages.inc b/core/modules/locale/locale.pages.inc
index 3b2d2abc9a3..aaabec72a30 100644
--- a/core/modules/locale/locale.pages.inc
+++ b/core/modules/locale/locale.pages.inc
@@ -75,7 +75,9 @@ function _locale_translate_seek() {
     $limit_language = $query['language'];
   }
 
-  $sql_query = $sql_query->extend('PagerDefault')->limit(50);
+  $sql_query = $sql_query
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->limit(50);
   $locales = $sql_query->execute();
 
   $header = array(t('String'), t('Context'), ($limit_language) ? t('Language') : t('Languages'), array('data' => t('Operations'), 'colspan' => '2'));
diff --git a/core/modules/node/node.admin.inc b/core/modules/node/node.admin.inc
index ac362e82324..c933daaa2dc 100644
--- a/core/modules/node/node.admin.inc
+++ b/core/modules/node/node.admin.inc
@@ -447,7 +447,9 @@ function node_admin_nodes() {
   }
   $header['operations'] = array('data' => t('Operations'));
 
-  $query = db_select('node', 'n')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('node', 'n')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   node_build_filter_query($query);
 
   if (!user_access('bypass node access')) {
diff --git a/core/modules/node/node.module b/core/modules/node/node.module
index d2d4bad5149..671d0f09922 100644
--- a/core/modules/node/node.module
+++ b/core/modules/node/node.module
@@ -1519,7 +1519,9 @@ function node_search_admin() {
  */
 function node_search_execute($keys = NULL, $conditions = NULL) {
   // Build matching conditions
-  $query = db_select('search_index', 'i', array('target' => 'slave'))->extend('Drupal\search\SearchQuery')->extend('PagerDefault');
+  $query = db_select('search_index', 'i', array('target' => 'slave'))
+    ->extend('Drupal\search\SearchQuery')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
   $query->join('node', 'n', 'n.nid = i.sid');
   $query
     ->condition('n.status', 1)
@@ -2488,7 +2490,7 @@ function node_page_default() {
     ->condition('status', 1)
     ->orderBy('sticky', 'DESC')
     ->orderBy('created', 'DESC')
-    ->extend('PagerDefault')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
     ->limit(variable_get('default_nodes_main', 10))
     ->addTag('node_access');
 
diff --git a/core/modules/path/path.admin.inc b/core/modules/path/path.admin.inc
index a45565ad1c9..a884f9eaeaf 100644
--- a/core/modules/path/path.admin.inc
+++ b/core/modules/path/path.admin.inc
@@ -27,7 +27,9 @@ function path_admin_overview($keys = NULL) {
   }
   $header[] = array('data' => t('Operations'));
 
-  $query = db_select('url_alias')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('url_alias')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   if ($keys) {
     // Replace wildcards with PDO wildcards.
     $query->condition('alias', '%' . preg_replace('!\*+!', '%', $keys) . '%', 'LIKE');
diff --git a/core/modules/poll/poll.pages.inc b/core/modules/poll/poll.pages.inc
index 15f3ba79055..b04f99ccb05 100644
--- a/core/modules/poll/poll.pages.inc
+++ b/core/modules/poll/poll.pages.inc
@@ -29,7 +29,7 @@ function poll_page() {
     ->groupBy('n.title')
     ->groupBy('p.active')
     ->groupBy('n.created')
-    ->extend('PagerDefault')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
     ->limit($polls_per_page)
     ->addTag('node_access');
   $select->setCountQuery($count_select);
@@ -56,7 +56,9 @@ function poll_votes($node) {
   $header[] = array('data' => t('Vote'), 'field' => 'pc.chtext');
   $header[] = array('data' => t('Timestamp'), 'field' => 'pv.timestamp', 'sort' => 'desc');
 
-  $select = db_select('poll_vote', 'pv')->extend('PagerDefault')->extend('TableSort');
+  $select = db_select('poll_vote', 'pv')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $select->join('poll_choice', 'pc', 'pv.chid = pc.chid');
   $select->join('users', 'u', 'pv.uid = u.uid');
   $queried_votes = $select
diff --git a/core/modules/search/search.api.php b/core/modules/search/search.api.php
index cf8192242ed..0f43460697e 100644
--- a/core/modules/search/search.api.php
+++ b/core/modules/search/search.api.php
@@ -157,8 +157,8 @@ function hook_search_admin() {
 /**
  * Execute a search for a set of key words.
  *
- * Use database API with the 'PagerDefault' query extension to perform your
- * search.
+ * Use database API with the 'Drupal\Core\Database\Query\PagerSelectExtender'
+ * query extension to perform your search.
  *
  * If your module uses hook_update_index() and search_index() to index its
  * items, use table 'search_index' aliased to 'i' as the main table in your
@@ -195,7 +195,9 @@ function hook_search_admin() {
  */
 function hook_search_execute($keys = NULL, $conditions = NULL) {
   // Build matching conditions
-  $query = db_select('search_index', 'i', array('target' => 'slave'))->extend('Drupal\search\SearchQuery')->extend('PagerDefault');
+  $query = db_select('search_index', 'i', array('target' => 'slave'))
+    ->extend('Drupal\search\SearchQuery')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
   $query->join('node', 'n', 'n.nid = i.sid');
   $query
     ->condition('n.status', 1)
diff --git a/core/modules/statistics/statistics.admin.inc b/core/modules/statistics/statistics.admin.inc
index ea608a43c93..84bf60d93ad 100644
--- a/core/modules/statistics/statistics.admin.inc
+++ b/core/modules/statistics/statistics.admin.inc
@@ -25,7 +25,9 @@ function statistics_recent_hits() {
     array('data' => t('Operations'))
   );
 
-  $query = db_select('accesslog', 'a', array('target' => 'slave'))->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('accesslog', 'a', array('target' => 'slave'))
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->join('users', 'u', 'a.uid = u.uid');
   $query
     ->fields('a', array('aid', 'timestamp', 'path', 'title', 'uid'))
@@ -71,7 +73,9 @@ function statistics_top_pages() {
     array('data' => t('Total page generation time'), 'field' => 'total_time')
   );
 
-  $query = db_select('accesslog', 'a', array('target' => 'slave'))->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('accesslog', 'a', array('target' => 'slave'))
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->addExpression('COUNT(path)', 'hits');
   // MAX(title) avoids having empty node titles which otherwise causes
   // duplicates in the top pages list.
@@ -124,7 +128,9 @@ function statistics_top_visitors() {
     array('data' => t('Total page generation time'), 'field' => 'total'),
     array('data' => user_access('block IP addresses') ? t('Operations') : '', 'colspan' => 2),
   );
-  $query = db_select('accesslog', 'a', array('target' => 'slave'))->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('accesslog', 'a', array('target' => 'slave'))
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query->leftJoin('blocked_ips', 'bl', 'a.hostname = bl.ip');
   $query->leftJoin('users', 'u', 'a.uid = u.uid');
 
@@ -184,7 +190,9 @@ function statistics_top_referrers() {
     array('data' => t('Url'), 'field' => 'url'),
     array('data' => t('Last visit'), 'field' => 'last'),
   );
-  $query = db_select('accesslog', 'a')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('accesslog', 'a')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
 
   $query->addExpression('COUNT(url)', 'hits');
   $query->addExpression('MAX(timestamp)', 'last');
diff --git a/core/modules/statistics/statistics.pages.inc b/core/modules/statistics/statistics.pages.inc
index 586189aad1b..524d59e51e7 100644
--- a/core/modules/statistics/statistics.pages.inc
+++ b/core/modules/statistics/statistics.pages.inc
@@ -25,7 +25,9 @@ function statistics_node_tracker() {
         array('data' => t('User'), 'field' => 'u.name'),
         array('data' => t('Operations')));
 
-    $query = db_select('accesslog', 'a', array('target' => 'slave'))->extend('PagerDefault')->extend('TableSort');
+    $query = db_select('accesslog', 'a', array('target' => 'slave'))
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+      ->extend('TableSort');
     $query->join('users', 'u', 'a.uid = u.uid');
 
     $query
@@ -79,7 +81,9 @@ function statistics_user_tracker() {
         array('data' => t('Timestamp'), 'field' => 'timestamp', 'sort' => 'desc'),
         array('data' => t('Page'), 'field' => 'path'),
         array('data' => t('Operations')));
-    $query = db_select('accesslog', 'a', array('target' => 'slave'))->extend('PagerDefault')->extend('TableSort');
+    $query = db_select('accesslog', 'a', array('target' => 'slave'))
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+      ->extend('TableSort');
     $query
       ->fields('a', array('aid', 'timestamp', 'path', 'title'))
       ->condition('uid', $account->uid)
diff --git a/core/modules/system/system.admin.inc b/core/modules/system/system.admin.inc
index a31e278483c..626bf70e617 100644
--- a/core/modules/system/system.admin.inc
+++ b/core/modules/system/system.admin.inc
@@ -2921,7 +2921,9 @@ function system_actions_manage() {
     array('data' => t('Label'), 'field' => 'label'),
     array('data' => $instances_present ? t('Operations') : '', 'colspan' => '2')
   );
-  $query = db_select('actions')->extend('PagerDefault')->extend('TableSort');
+  $query = db_select('actions')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $result = $query
     ->fields('actions')
     ->limit(50)
diff --git a/core/modules/system/tests/database.test b/core/modules/system/tests/database.test
index 889a30ced70..ef0807be301 100644
--- a/core/modules/system/tests/database.test
+++ b/core/modules/system/tests/database.test
@@ -2087,7 +2087,7 @@ class DatabaseSelectComplexTestCase extends DatabaseTestCase {
 
   function testHavingCountQuery() {
     $query = db_select('test')
-      ->extend('PagerDefault')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
       ->groupBy('age')
       ->having('age + 1 > 0');
     $query->addField('test', 'age');
@@ -2352,7 +2352,8 @@ class DatabaseSelectPagerDefaultTestCase extends DatabaseTestCase {
    * This is a regression test for #467984.
    */
   function testInnerPagerQuery() {
-    $query = db_select('test', 't')->extend('PagerDefault');
+    $query = db_select('test', 't')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
     $query
       ->fields('t', array('age'))
       ->orderBy('age')
@@ -2373,7 +2374,8 @@ class DatabaseSelectPagerDefaultTestCase extends DatabaseTestCase {
    * This is a regression test for #467984.
    */
   function testHavingPagerQuery() {
-    $query = db_select('test', 't')->extend('PagerDefault');
+    $query = db_select('test', 't')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
     $query
       ->fields('t', array('name'))
       ->orderBy('name')
@@ -2393,7 +2395,8 @@ class DatabaseSelectPagerDefaultTestCase extends DatabaseTestCase {
   function testElementNumbers() {
     $_GET['page'] = '3, 2, 1, 0';
 
-    $name = db_select('test', 't')->extend('PagerDefault')
+    $name = db_select('test', 't')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
       ->element(2)
       ->fields('t', array('name'))
       ->orderBy('age')
@@ -2404,7 +2407,8 @@ class DatabaseSelectPagerDefaultTestCase extends DatabaseTestCase {
 
     // Setting an element smaller than the previous one
     // should not overwrite the pager $maxElement with a smaller value.
-    $name = db_select('test', 't')->extend('PagerDefault')
+    $name = db_select('test', 't')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
       ->element(1)
       ->fields('t', array('name'))
       ->orderBy('age')
@@ -2413,7 +2417,8 @@ class DatabaseSelectPagerDefaultTestCase extends DatabaseTestCase {
       ->fetchField();
     $this->assertEqual($name, 'George', t('Pager query #2 with a specified element ID returned the correct results.'));
 
-    $name = db_select('test', 't')->extend('PagerDefault')
+    $name = db_select('test', 't')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
       ->fields('t', array('name'))
       ->orderBy('age')
       ->limit(1)
diff --git a/core/modules/system/tests/modules/database_test/database_test.module b/core/modules/system/tests/modules/database_test/database_test.module
index 0ab51d80747..f248e5a0082 100644
--- a/core/modules/system/tests/modules/database_test/database_test.module
+++ b/core/modules/system/tests/modules/database_test/database_test.module
@@ -105,7 +105,9 @@ function database_test_even_pager_query($limit) {
     ->orderBy('age');
 
   // This should result in 2 pages of results.
-  $query = $query->extend('PagerDefault')->limit($limit);
+  $query = $query
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->limit($limit);
 
   $names = $query->execute()->fetchCol();
 
@@ -129,7 +131,9 @@ function database_test_odd_pager_query($limit) {
     ->orderBy('pid');
 
   // This should result in 4 pages of results.
-  $query = $query->extend('PagerDefault')->limit($limit);
+  $query = $query
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->limit($limit);
 
   $names = $query->execute()->fetchCol();
 
@@ -213,7 +217,9 @@ function database_test_theme_tablesort($form, &$form_state) {
   $count_query = clone $query;
   $count_query->addExpression('COUNT(u.uid)');
 
-  $query = $query->extend('PagerDefault')->extend('TableSort');
+  $query = $query
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query
     ->fields('u', array('uid', 'name', 'status', 'created', 'access'))
     ->limit(50)
diff --git a/core/modules/taxonomy/taxonomy.module b/core/modules/taxonomy/taxonomy.module
index b536b080384..4778f84d2f5 100644
--- a/core/modules/taxonomy/taxonomy.module
+++ b/core/modules/taxonomy/taxonomy.module
@@ -233,7 +233,7 @@ function taxonomy_select_nodes($tid, $pager = TRUE, $limit = FALSE, $order = arr
     $count_query = clone $query;
     $count_query->addExpression('COUNT(t.nid)');
 
-    $query = $query->extend('PagerDefault');
+    $query = $query->extend('Drupal\Core\Database\Query\PagerSelectExtender');
     if ($limit !== FALSE) {
       $query = $query->limit($limit);
     }
diff --git a/core/modules/tracker/tracker.pages.inc b/core/modules/tracker/tracker.pages.inc
index 30583be3656..3f9728d990a 100644
--- a/core/modules/tracker/tracker.pages.inc
+++ b/core/modules/tracker/tracker.pages.inc
@@ -19,7 +19,8 @@
  */
 function tracker_page($account = NULL, $set_title = FALSE) {
   if ($account) {
-    $query = db_select('tracker_user', 't')->extend('PagerDefault');
+    $query = db_select('tracker_user', 't')
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
     $query->condition('t.uid', $account->uid);
 
     if ($set_title) {
@@ -30,7 +31,8 @@ function tracker_page($account = NULL, $set_title = FALSE) {
     }
   }
   else {
-    $query = db_select('tracker_node', 't', array('target' => 'slave'))->extend('PagerDefault');
+    $query = db_select('tracker_node', 't', array('target' => 'slave'))
+      ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
   }
 
   // This array acts as a placeholder for the data selected later
diff --git a/core/modules/user/user.admin.inc b/core/modules/user/user.admin.inc
index c65883ace6b..50d86b063bf 100644
--- a/core/modules/user/user.admin.inc
+++ b/core/modules/user/user.admin.inc
@@ -158,7 +158,9 @@ function user_admin_account() {
   $count_query = clone $query;
   $count_query->addExpression('COUNT(u.uid)');
 
-  $query = $query->extend('PagerDefault')->extend('TableSort');
+  $query = $query
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender')
+    ->extend('TableSort');
   $query
     ->fields('u', array('uid', 'name', 'status', 'created', 'access'))
     ->limit(50)
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index d023f50af48..80077216033 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -641,7 +641,8 @@ function user_search_execute($keys = NULL, $conditions = NULL) {
   $find = array();
   // Replace wildcards with MySQL/PostgreSQL wildcards.
   $keys = preg_replace('!\*+!', '%', $keys);
-  $query = db_select('users')->extend('PagerDefault');
+  $query = db_select('users')
+    ->extend('Drupal\Core\Database\Query\PagerSelectExtender');
   $query->fields('users', array('uid'));
   if (user_access('administer users')) {
     // Administrators can also search in the otherwise private email field.