diff --git a/lib/SimpleSAML/Database.php b/lib/SimpleSAML/Database.php
index 1012e116e6d7cf7add3a6774b648dbfd4c8372a0..b703557c9e75f1325bf64f77ce576fb027b46409 100644
--- a/lib/SimpleSAML/Database.php
+++ b/lib/SimpleSAML/Database.php
@@ -2,17 +2,15 @@
 namespace SimpleSAML;
 
 /**
- * This file implements functions to read and write to a group of database
- * servers.
+ * This file implements functions to read and write to a group of database servers.
  *
- * This database class supports a single database, or a master/slave
- * configuration with as many defined slaves as a user would like.
+ * This database class supports a single database, or a master/slave configuration with as many defined slaves as a
+ * user would like.
  *
- * The goal of this class is to provide a single mechanism to connect to a database
- * that can be reused by any component within SimpleSAMLphp including modules.
- * When using this class, the global configuration should be passed here, but
- * in the case of a module that has a good reason to use a different database,
- * such as sqlauth, an alternative config file can be provided.
+ * The goal of this class is to provide a single mechanism to connect to a database that can be reused by any component
+ * within SimpleSAMLphp including modules. When using this class, the global configuration should be passed here, but in
+ * the case of a module that has a good reason to use a different database, such as sqlauth, an alternative config file
+ * can be provided.
  *
  * @author Tyler Antonio, University of Alberta. <tantonio@ualberta.ca>
  * @package SimpleSAMLphp
@@ -32,8 +30,7 @@ class Database
     private $dbMaster;
 
     /**
-     * Array of PDO Objects for configured database
-     * slaves
+     * Array of PDO Objects for configured database slaves
      */
     private $dbSlaves = array();
 
@@ -112,8 +109,7 @@ class Database
 
 
     /**
-     * Generate an Instance ID based on the database
-     * configuration.
+     * Generate an Instance ID based on the database configuration.
      *
      * @param \SimpleSAML_Configuration $config Configuration class
      *
@@ -161,9 +157,8 @@ class Database
 
 
     /**
-     * This function randomly selects a slave database server
-     * to query. In the event no slaves are configured, it
-     * will return the master.
+     * This function randomly selects a slave database server to query. In the event no slaves are configured, it will
+     * return the master.
      *
      * @return \PDO object
      */
@@ -229,14 +224,13 @@ class Database
 
 
     /**
-     * This function queries the database without using a
-     * prepared statement.
+     * This function queries the database without using a prepared statement.
      *
      * @param \PDO   $db PDO object to use
-     * @param string $stmt Prepared SQL statement
+     * @param string $stmt An SQL statement to execute, previously escaped.
      *
      * @throws \Exception If an error happens while trying to execute the query.
-     * @return \PDOStatement object
+     * @return int The number of rows affected.
      */
     private function exec($db, $stmt)
     {
@@ -244,9 +238,7 @@ class Database
         assert('is_string($stmt)');
 
         try {
-            $query = $db->exec($stmt);
-
-            return $query;
+            return $db->exec($stmt);
         } catch (\PDOException $e) {
             $this->lastError = $db->errorInfo();
             throw new \Exception("Database error: ".$e->getMessage());
@@ -276,8 +268,7 @@ class Database
 
 
     /**
-     * This executes queries on a database server
-     * that is determined by this::getSlave()
+     * This executes queries on a database server that is determined by this::getSlave().
      *
      * @param string $stmt Prepared SQL statement
      * @param array  $params Parameters