diff --git a/lib/dml/database_column_info.php b/lib/dml/database_column_info.php
index b6198838689..4aee79aa35e 100644
--- a/lib/dml/database_column_info.php
+++ b/lib/dml/database_column_info.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,13 +14,10 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Database column information.
  *
- * @package    core
- * @category   dml
- * @subpackage dml
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -34,10 +30,9 @@ defined('MOODLE_INTERNAL') || die();
  * It is based on the adodb library's ADOFieldObject object.
  * 'column' does mean 'the field' here.
  *
- * @package core
- * @category dml
- * @copyright 2008 Petr Skoda (http://skodak.org)
- * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @package    core_dml
+ * @copyright  2008 Petr Skoda (http://skodak.org)
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 class database_column_info {
     /**
diff --git a/lib/dml/moodle_database.php b/lib/dml/moodle_database.php
index faf097e074c..48a992c73eb 100644
--- a/lib/dml/moodle_database.php
+++ b/lib/dml/moodle_database.php
@@ -14,24 +14,19 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Abstract database driver class.
  *
- * @package core
- * @category dml
- * @subpackage dml
- * @copyright 2008 Petr Skoda (http://skodak.org)
- * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ * @package    core_dml
+ * @copyright  2008 Petr Skoda (http://skodak.org)
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/database_column_info.php');
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
-require_once($CFG->libdir.'/dml/moodle_transaction.php');
-
-/// GLOBAL CONSTANTS /////////////////////////////////////////////////////////
+require_once(__DIR__.'/database_column_info.php');
+require_once(__DIR__.'/moodle_recordset.php');
+require_once(__DIR__.'/moodle_transaction.php');
 
 /** SQL_PARAMS_NAMED - Bitmask, indicates :name type parameters are supported by db backend. */
 define('SQL_PARAMS_NAMED', 1);
@@ -61,8 +56,7 @@ define('SQL_QUERY_AUX', 5);
  * Abstract class representing moodle database interface.
  * @link http://docs.moodle.org/dev/DML_functions
  *
- * @package    core
- * @category   dml
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -89,7 +83,7 @@ abstract class moodle_database {
     /** @var string Prefix added to table names. */
     protected $prefix;
 
-    /** @var array Database or driver specific options, such as sockets or TCPIP db connections. */
+    /** @var array Database or driver specific options, such as sockets or TCP/IP db connections. */
     protected $dboptions;
 
     /** @var bool True means non-moodle external database used.*/
@@ -324,7 +318,7 @@ abstract class moodle_database {
             $backtrace = $lowesttransaction->get_backtrace();
 
             if (defined('PHPUNIT_TEST') and PHPUNIT_TEST) {
-                //no need to log sudden exits in our PHPunit test cases
+                //no need to log sudden exits in our PHPUnit test cases
             } else {
                 error_log('Potential coding error - active database transaction detected when disposing database:'."\n".format_backtrace($backtrace, true));
             }
@@ -422,7 +416,7 @@ abstract class moodle_database {
 
     /**
      * This logs the last query based on 'logall', 'logslow' and 'logerrors' options configured via $CFG->dboptions .
-     * @param string $error or false if not error
+     * @param string|bool $error or false if not error
      * @return void
      */
     public function query_log($error=false) {
@@ -463,7 +457,7 @@ abstract class moodle_database {
 
     /**
      * Returns database server info array
-     * @return array Array containing 'description' and 'version' atleast.
+     * @return array Array containing 'description' and 'version' at least.
      */
     public abstract function get_server_info();
 
@@ -687,6 +681,7 @@ abstract class moodle_database {
      * Internal private utitlity function used to fix parameters.
      * Used with {@link preg_replace_callback()}
      * @param array $match Refer to preg_replace_callback usage for description.
+     * @return string
      */
     private function _fix_sql_params_dollar_callback($match) {
         $this->fix_sql_params_i++;
@@ -697,6 +692,7 @@ abstract class moodle_database {
      * Detects object parameters and throws exception if found
      * @param mixed $value
      * @return void
+     * @throws coding_exception if object detected
      */
     protected function detect_objects($value) {
         if (is_object($value)) {
@@ -723,7 +719,7 @@ abstract class moodle_database {
             $params[$key] = is_bool($value) ? (int)$value : $value;
         }
 
-        // NICOLAS C: Fixed regexp for negative backwards lookahead of double colons. Thanks for Sam Marshall's help
+        // NICOLAS C: Fixed regexp for negative backwards look-ahead of double colons. Thanks for Sam Marshall's help
         $named_count = preg_match_all('/(?<!:):[a-z][a-z0-9_]*/', $sql, $named_matches); // :: used in pgsql casts
         $dollar_count = preg_match_all('/\$[1-9][0-9]*/', $sql, $dollar_matches);
         $q_count     = substr_count($sql, '?');
@@ -1509,7 +1505,6 @@ abstract class moodle_database {
      */
     public abstract function update_record($table, $dataobject, $bulk=false);
 
-
     /**
      * Set a single field in every table record where all the given conditions met.
      *
@@ -1685,9 +1680,6 @@ abstract class moodle_database {
      */
     public abstract function delete_records_select($table, $select, array $params=null);
 
-
-
-// sql constructs
     /**
      * Returns the FROM clause required by some DBs in all SELECT statements.
      *
@@ -1907,7 +1899,7 @@ abstract class moodle_database {
      * because it's really slooooooow.
      *
      * @param string $fieldname The name of the TEXT field we need to order by.
-     * @param string $numchars The number of chars to use for the ordering (defaults to 32).
+     * @param int $numchars The number of chars to use for the ordering (defaults to 32).
      * @return string The piece of SQL code to be used in your statement.
      */
     public function sql_order_by_text($fieldname, $numchars=32) {
@@ -2050,8 +2042,6 @@ abstract class moodle_database {
         return '';
     }
 
-// transactions
-
     /**
      * Checks and returns true if transactions are supported.
      *
@@ -2079,6 +2069,7 @@ abstract class moodle_database {
      * This is a test that throws an exception if transaction in progress.
      * This test does not force rollback of active transactions.
      * @return void
+     * @throws dml_transaction_exception if stansaction active
      */
     public function transactions_forbidden() {
         if ($this->is_transaction_started()) {
@@ -2232,7 +2223,6 @@ abstract class moodle_database {
         $this->force_rollback = false;
     }
 
-// session locking
     /**
      * Is session lock supported in this driver?
      * @return bool
@@ -2261,7 +2251,6 @@ abstract class moodle_database {
     public function release_session_lock($rowid) {
     }
 
-// performance and logging
     /**
      * Returns the number of reads done by this database.
      * @return int Number of reads.
diff --git a/lib/dml/moodle_recordset.php b/lib/dml/moodle_recordset.php
index d1e7005120a..975b253d79e 100644
--- a/lib/dml/moodle_recordset.php
+++ b/lib/dml/moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,13 +14,10 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Abstract recordset.
  *
- * @package    core
- * @category   dml
- * @subpackage dml
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
diff --git a/lib/dml/moodle_temptables.php b/lib/dml/moodle_temptables.php
index c89348ae1da..19f0c20ce78 100644
--- a/lib/dml/moodle_temptables.php
+++ b/lib/dml/moodle_temptables.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -35,9 +34,7 @@
  * Only drivers needing it will use this store. Neither moodle_database (abstract) or
  * databases like postgres need this, because they don't lack any temp functionality.
  *
- * @package    core
- * @category   dml
- * @subpackage dml
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
diff --git a/lib/dml/moodle_transaction.php b/lib/dml/moodle_transaction.php
index 7709df23aaa..106ffb8da5e 100644
--- a/lib/dml/moodle_transaction.php
+++ b/lib/dml/moodle_transaction.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,13 +14,10 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Delegated database transaction support.
  *
- * @package    core
- * @category   dml
- * @subpackage dml
+ * @package    core_dml
  * @copyright  2009 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -31,9 +27,7 @@ defined('MOODLE_INTERNAL') || die();
 /**
  * Delegated transaction class.
  *
- * @package    core
- * @category   dml
- * @subpackage dml
+ * @package    core_dml
  * @copyright  2009 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -110,4 +104,4 @@ class moodle_transaction {
         }
         $this->database->rollback_delegated_transaction($this, $e);
     }
-}
\ No newline at end of file
+}
diff --git a/lib/dml/mssql_native_moodle_database.php b/lib/dml/mssql_native_moodle_database.php
index 5ae728e86c6..7d134d2fc61 100644
--- a/lib/dml/mssql_native_moodle_database.php
+++ b/lib/dml/mssql_native_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,27 +14,24 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Native mssql class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_database.php');
-require_once($CFG->libdir.'/dml/mssql_native_moodle_recordset.php');
-require_once($CFG->libdir.'/dml/mssql_native_moodle_temptables.php');
+require_once(__DIR__.'/moodle_database.php');
+require_once(__DIR__.'/mssql_native_moodle_recordset.php');
+require_once(__DIR__.'/mssql_native_moodle_temptables.php');
 
 /**
  * Native mssql class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -515,7 +511,7 @@ class mssql_native_moodle_database extends moodle_database {
     protected function normalise_value($column, $value) {
         $this->detect_objects($value);
 
-        if (is_bool($value)) { /// Always, convert boolean to int
+        if (is_bool($value)) { // Always, convert boolean to int
             $value = (int)$value;
         } // And continue processing because text columns with numeric info need special handling below
 
@@ -619,7 +615,7 @@ class mssql_native_moodle_database extends moodle_database {
         if (empty($params)) {
             return $sql;
         }
-        /// ok, we have verified sql statement with ? and correct number of params
+        // ok, we have verified sql statement with ? and correct number of params
         $parts = explode('?', $sql);
         $return = array_shift($parts);
         foreach ($params as $param) {
@@ -1039,7 +1035,7 @@ class mssql_native_moodle_database extends moodle_database {
         // convert params to ? types
         list($select, $params, $type) = $this->fix_sql_params($select, $params);
 
-    /// Get column metadata
+        // Get column metadata
         $columns = $this->get_columns($table);
         $column = $columns[$newfield];
 
@@ -1094,8 +1090,6 @@ class mssql_native_moodle_database extends moodle_database {
         return true;
     }
 
-/// SQL helper functions
-
     public function sql_cast_char2int($fieldname, $text=false) {
         if (!$text) {
             return ' CAST(' . $fieldname . ' AS INT) ';
@@ -1251,8 +1245,6 @@ s only returning name of SQL substring function, it now requires all parameters.
         }
     }
 
-/// session locking
-
     public function session_lock_supported() {
         return true;
     }
@@ -1315,8 +1307,6 @@ s only returning name of SQL substring function, it now requires all parameters.
         $this->free_result($result);
     }
 
-/// transactions
-
     /**
      * Driver specific start of real database transaction,
      * this can not be used directly in code.
diff --git a/lib/dml/mssql_native_moodle_recordset.php b/lib/dml/mssql_native_moodle_recordset.php
index d383d31860b..2c7b7110fbd 100644
--- a/lib/dml/mssql_native_moodle_recordset.php
+++ b/lib/dml/mssql_native_moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -18,15 +17,14 @@
 /**
  * MSSQL specific recordset.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
+require_once(__DIR__.'/moodle_recordset.php');
 
 class mssql_native_moodle_recordset extends moodle_recordset {
 
@@ -54,7 +52,7 @@ class mssql_native_moodle_recordset extends moodle_recordset {
     }
 
     public function key() {
-    /// return first column value as key
+        // return first column value as key
         if (!$this->current) {
             return false;
         }
diff --git a/lib/dml/mssql_native_moodle_temptables.php b/lib/dml/mssql_native_moodle_temptables.php
index 9242059978b..df04cca1d03 100644
--- a/lib/dml/mssql_native_moodle_temptables.php
+++ b/lib/dml/mssql_native_moodle_temptables.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -20,15 +19,14 @@
  * are named differently than normal tables. Also used to be able to retrieve
  * temp table names included in the get_tables() method of the DB.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_temptables.php');
+require_once(__DIR__.'/moodle_temptables.php');
 
 class mssql_native_moodle_temptables extends moodle_temptables {
 
@@ -50,5 +48,4 @@ class mssql_native_moodle_temptables extends moodle_temptables {
         // TODO: throw exception if exists: if ($this->is_temptable...
         $this->temptables[$tablename] = '#' . $this->prefix . $tablename;
     }
-
 }
diff --git a/lib/dml/mysqli_native_moodle_database.php b/lib/dml/mysqli_native_moodle_database.php
index 535eca61fe8..93311bd5fd4 100644
--- a/lib/dml/mysqli_native_moodle_database.php
+++ b/lib/dml/mysqli_native_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,27 +14,24 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Native mysqli class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_database.php');
-require_once($CFG->libdir.'/dml/mysqli_native_moodle_recordset.php');
-require_once($CFG->libdir.'/dml/mysqli_native_moodle_temptables.php');
+require_once(__DIR__.'/moodle_database.php');
+require_once(__DIR__.'/mysqli_native_moodle_recordset.php');
+require_once(__DIR__.'/mysqli_native_moodle_temptables.php');
 
 /**
  * Native mysqli class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -77,7 +73,7 @@ class mysqli_native_moodle_database extends moodle_database {
             $dbport = 3306;
         }
         ob_start();
-        $conn = new mysqli($dbhost, $dbuser, $dbpass, '', $dbport, $dbsocket); /// Connect without db
+        $conn = new mysqli($dbhost, $dbuser, $dbpass, '', $dbport, $dbsocket); // Connect without db
         $dberr = ob_get_contents();
         ob_end_clean();
         $errorno = @$conn->connect_errno;
@@ -324,7 +320,7 @@ class mysqli_native_moodle_database extends moodle_database {
             $this->query_end($result);
         }
 
-        // Connection stabilished and configured, going to instantiate the temptables controller
+        // Connection stabilised and configured, going to instantiate the temptables controller
         $this->temptables = new mysqli_native_moodle_temptables($this);
 
         return true;
@@ -736,7 +732,7 @@ class mysqli_native_moodle_database extends moodle_database {
         if (empty($params)) {
             return $sql;
         }
-        /// ok, we have verified sql statement with ? and correct number of params
+        // ok, we have verified sql statement with ? and correct number of params
         $parts = explode('?', $sql);
         $return = array_shift($parts);
         foreach ($params as $param) {
@@ -1264,7 +1260,6 @@ class mysqli_native_moodle_database extends moodle_database {
         return ' CAST(' . $fieldname . ' AS SIGNED) ';
     }
 
-/// session locking
     public function session_lock_supported() {
         return true;
     }
@@ -1273,7 +1268,7 @@ class mysqli_native_moodle_database extends moodle_database {
      * Obtain session lock
      * @param int $rowid id of the row with session record
      * @param int $timeout max allowed time to wait for the lock in seconds
-     * @return bool success
+     * @return void
      */
     public function get_session_lock($rowid, $timeout) {
         parent::get_session_lock($rowid, $timeout);
@@ -1309,7 +1304,6 @@ class mysqli_native_moodle_database extends moodle_database {
         }
     }
 
-/// transactions
     /**
      * Are transactions supported?
      * It is not responsible to run productions servers
diff --git a/lib/dml/mysqli_native_moodle_recordset.php b/lib/dml/mysqli_native_moodle_recordset.php
index e8dc5bce994..230ef8c6edc 100644
--- a/lib/dml/mysqli_native_moodle_recordset.php
+++ b/lib/dml/mysqli_native_moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,19 +14,17 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Mysqli specific recordset.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
+require_once(__DIR__.'/moodle_recordset.php');
 
 /**
  * Mysqli specific moodle recordset class
@@ -63,7 +60,7 @@ class mysqli_native_moodle_recordset extends moodle_recordset {
     }
 
     public function key() {
-    /// return first column value as key
+        // return first column value as key
         if (!$this->current) {
             return false;
         }
diff --git a/lib/dml/mysqli_native_moodle_temptables.php b/lib/dml/mysqli_native_moodle_temptables.php
index 0ad5132328f..4d777be009b 100644
--- a/lib/dml/mysqli_native_moodle_temptables.php
+++ b/lib/dml/mysqli_native_moodle_temptables.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -20,16 +19,15 @@
  * are named differently than normal tables. Also used to be able to retrieve
  * temp table names included in the get_tables() method of the DB.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_temptables.php');
+require_once(__DIR__.'/moodle_temptables.php');
 
 class mysqli_native_moodle_temptables extends moodle_temptables {
-    /// I love these classes :-P
+    // I love these classes :-P
 }
diff --git a/lib/dml/oci_native_moodle_database.php b/lib/dml/oci_native_moodle_database.php
index 08df721afd2..b62ac9baddc 100644
--- a/lib/dml/oci_native_moodle_database.php
+++ b/lib/dml/oci_native_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,21 +14,19 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Native oci class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_database.php');
-require_once($CFG->libdir.'/dml/oci_native_moodle_recordset.php');
-require_once($CFG->libdir.'/dml/oci_native_moodle_temptables.php');
+require_once(__DIR__.'/moodle_database.php');
+require_once(__DIR__.'/oci_native_moodle_recordset.php');
+require_once(__DIR__.'/oci_native_moodle_temptables.php');
 
 /**
  * Native oci class representing moodle database interface.
@@ -37,8 +34,7 @@ require_once($CFG->libdir.'/dml/oci_native_moodle_temptables.php');
  * One complete reference for PHP + OCI:
  * http://www.oracle.com/technology/tech/php/underground-php-oracle-manual.html
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -809,7 +805,7 @@ class oci_native_moodle_database extends moodle_database {
         // of empties will need to use the sql_empty() and sql_isempty() helper functions.
         // MDL-17491.
 
-        // If the field ins't VARCHAR or CLOB, skip
+        // If the field isn't VARCHAR or CLOB, skip
         if ($column->meta_type != 'C' and $column->meta_type != 'X') {
             return $value;
         }
@@ -835,7 +831,7 @@ class oci_native_moodle_database extends moodle_database {
             return '0'; // Transform 0 to '0' that evaluates the same for PHP
 
         } else if ($value === '') {
-            return ' '; // Transform '' to ' ' that DONT'T EVALUATE THE SAME
+            return ' '; // Transform '' to ' ' that DON'T EVALUATE THE SAME
                         // (we'll transform back again on get_records_XXX functions and others)!!
         }
 
@@ -1449,7 +1445,6 @@ class oci_native_moodle_database extends moodle_database {
         return ' FROM dual';
     }
 
-// Bitwise operations
    protected function bitwise_supported() {
         if (isset($this->bitwise_supported)) { // Use cached value if available
             return $this->bitwise_supported;
@@ -1551,11 +1546,11 @@ class oci_native_moodle_database extends moodle_database {
         }
     }
 
-    // NOTE: Oracle concat implementation isn't ANSI compliant when using NULLs (the result of
-    // any concatenation with NULL must return NULL) because of his inability to differentiate
-    // NULLs and empty strings. So this function will cause some tests to fail. Hopefully
-    // it's only a side case and it won't affect normal concatenation operations in Moodle.
     public function sql_concat() {
+        // NOTE: Oracle concat implementation isn't ANSI compliant when using NULLs (the result of
+        // any concatenation with NULL must return NULL) because of his inability to differentiate
+        // NULLs and empty strings. So this function will cause some tests to fail. Hopefully
+        // it's only a side case and it won't affect normal concatenation operations in Moodle.
         $arr = func_get_args();
         $s = implode(' || ', $arr);
         if ($s === '') {
@@ -1604,7 +1599,6 @@ class oci_native_moodle_database extends moodle_database {
         return 'dbms_lob.substr(' . $fieldname . ', ' . $numchars . ',1)';
     }
 
-/// session locking
     public function session_lock_supported() {
         if (isset($this->dblocks_supported)) { // Use cached value if available
             return $this->dblocks_supported;
@@ -1629,7 +1623,7 @@ class oci_native_moodle_database extends moodle_database {
      * Obtain session lock
      * @param int $rowid id of the row with session record
      * @param int $timeout max allowed time to wait for the lock in seconds
-     * @return bool success
+     * @return void
      */
     public function get_session_lock($rowid, $timeout) {
         if (!$this->session_lock_supported()) {
@@ -1668,7 +1662,6 @@ class oci_native_moodle_database extends moodle_database {
         oci_free_statement($stmt);
     }
 
-/// transactions
     /**
      * Driver specific start of real database transaction,
      * this can not be used directly in code.
diff --git a/lib/dml/oci_native_moodle_package.sql b/lib/dml/oci_native_moodle_package.sql
index 042c6106645..2585f713d08 100644
--- a/lib/dml/oci_native_moodle_package.sql
+++ b/lib/dml/oci_native_moodle_package.sql
@@ -14,8 +14,7 @@
 -- along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 /**
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  * @version    20091010 (plz, keep this updated for easier reference)
diff --git a/lib/dml/oci_native_moodle_recordset.php b/lib/dml/oci_native_moodle_recordset.php
index 4d8694a54b1..e21e2310542 100644
--- a/lib/dml/oci_native_moodle_recordset.php
+++ b/lib/dml/oci_native_moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,19 +14,17 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Oracle specific recordset.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
+require_once(__DIR__.'/moodle_recordset.php');
 
 class oci_native_moodle_recordset extends moodle_recordset {
 
@@ -57,7 +54,7 @@ class oci_native_moodle_recordset extends moodle_recordset {
     }
 
     public function key() {
-    /// return first column value as key
+        // return first column value as key
         if (!$this->current) {
             return false;
         }
diff --git a/lib/dml/oci_native_moodle_temptables.php b/lib/dml/oci_native_moodle_temptables.php
index 1343d06dfe6..3b7fd3f7dd5 100644
--- a/lib/dml/oci_native_moodle_temptables.php
+++ b/lib/dml/oci_native_moodle_temptables.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -22,20 +21,21 @@
  * Also used to be able to retrieve temp table names included in the get_tables()
  * method of the DB.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_temptables.php');
+require_once(__DIR__.'/moodle_temptables.php');
 
 class oci_native_moodle_temptables extends moodle_temptables {
 
-    protected $unique_session_id; // To store unique_session_id. Needed for temp tables unique naming (upto 24cc)
-    protected $counter; // To get incrementally different temptable names on each add_temptable() request
+    /** @var int To store unique_session_id. Needed for temp tables unique naming (upto 24cc) */
+    protected $unique_session_id; //
+    /** @var int To get incrementally different temptable names on each add_temptable() request */
+    protected $counter;
 
     /**
      * Creates new moodle_temptables instance
@@ -50,7 +50,7 @@ class oci_native_moodle_temptables extends moodle_temptables {
     /**
      * Add one temptable to the store.
      *
-     * Overriden because OCI only support global temptables, so we need to change completely the name, based
+     * Overridden because OCI only support global temptables, so we need to change completely the name, based
      * in unique session identifier, to get local-like temp tables support
      * tables before the prefix.
      *
diff --git a/lib/dml/pdo_moodle_database.php b/lib/dml/pdo_moodle_database.php
index 8b090a49161..4aae9ce6ed6 100644
--- a/lib/dml/pdo_moodle_database.php
+++ b/lib/dml/pdo_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,26 +14,23 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Experimental pdo database class
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Andrei Bautu
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_database.php');
-require_once($CFG->libdir.'/dml/pdo_moodle_recordset.php');
+require_once(__DIR__.'/moodle_database.php');
+require_once(__DIR__.'/pdo_moodle_recordset.php');
 
 /**
  * Experimental pdo database class
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Andrei Bautu
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -102,7 +98,7 @@ abstract class pdo_moodle_database extends moodle_database {
     }
 
     protected function configure_dbconnection() {
-        ///TODO: not needed preconfigure_dbconnection() stuff for PDO drivers?
+        //TODO: not needed preconfigure_dbconnection() stuff for PDO drivers?
     }
 
     /**
diff --git a/lib/dml/pdo_moodle_recordset.php b/lib/dml/pdo_moodle_recordset.php
index 803416f590c..673d91f30b1 100644
--- a/lib/dml/pdo_moodle_recordset.php
+++ b/lib/dml/pdo_moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,25 +14,22 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Experimental pdo recordset
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Andrei Bautu
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
+require_once(__DIR__.'/moodle_recordset.php');
 
 /**
  * Experimental pdo recordset
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Andrei Bautu
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -64,7 +60,7 @@ class pdo_moodle_recordset extends moodle_recordset {
     }
 
     public function key() {
-    /// return first column value as key
+        // return first column value as key
         if (!$this->current) {
             return false;
         }
diff --git a/lib/dml/pgsql_native_moodle_database.php b/lib/dml/pgsql_native_moodle_database.php
index 57a007a9cd7..c883aed83e2 100644
--- a/lib/dml/pgsql_native_moodle_database.php
+++ b/lib/dml/pgsql_native_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,27 +14,24 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Native pgsql class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_database.php');
-require_once($CFG->libdir.'/dml/pgsql_native_moodle_recordset.php');
-require_once($CFG->libdir.'/dml/pgsql_native_moodle_temptables.php');
+require_once(__DIR__.'/moodle_database.php');
+require_once(__DIR__.'/pgsql_native_moodle_recordset.php');
+require_once(__DIR__.'/pgsql_native_moodle_temptables.php');
 
 /**
  * Native pgsql class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -566,7 +562,7 @@ class pgsql_native_moodle_database extends moodle_database {
      * @return bool
      */
     public function setup_is_unicodedb() {
-    /// Get PostgreSQL server_encoding value
+        // Get PostgreSQL server_encoding value
         $sql = "SHOW server_encoding";
         $this->query_start($sql, null, SQL_QUERY_AUX);
         $result = pg_query($this->pgsql, $sql);
@@ -1044,13 +1040,13 @@ class pgsql_native_moodle_database extends moodle_database {
         list($select, $params, $type) = $this->fix_sql_params($select, $params);
         $i = count($params)+1;
 
-    /// Get column metadata
+        // Get column metadata
         $columns = $this->get_columns($table);
         $column = $columns[$newfield];
 
         $normalised_value = $this->normalise_value($column, $newvalue);
         if (is_array($normalised_value) && array_key_exists('blob', $normalised_value)) {
-        /// Update BYTEA and return
+            // Update BYTEA and return
             $normalised_value = pg_escape_bytea($this->pgsql, $normalised_value['blob']);
             $sql = "UPDATE {$this->prefix}$table SET $newfield = '$normalised_value'::bytea $select";
             $this->query_start($sql, NULL, SQL_QUERY_UPDATE);
@@ -1152,7 +1148,7 @@ class pgsql_native_moodle_database extends moodle_database {
             return " '' ";
         }
         // Add always empty string element so integer-exclusive concats
-        // will work without needing to cast each element explicity
+        // will work without needing to cast each element explicitly
         return " '' || $s ";
     }
 
@@ -1175,7 +1171,6 @@ class pgsql_native_moodle_database extends moodle_database {
         return $positivematch ? '~*' : '!~*';
     }
 
-/// session locking
     public function session_lock_supported() {
         return true;
     }
@@ -1252,7 +1247,6 @@ class pgsql_native_moodle_database extends moodle_database {
         }
     }
 
-/// transactions
     /**
      * Driver specific start of real database transaction,
      * this can not be used directly in code.
diff --git a/lib/dml/pgsql_native_moodle_recordset.php b/lib/dml/pgsql_native_moodle_recordset.php
index 6d00d157f56..76fe53ea01f 100644
--- a/lib/dml/pgsql_native_moodle_recordset.php
+++ b/lib/dml/pgsql_native_moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,25 +14,22 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Native postgresql recordset.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
+require_once(__DIR__.'/moodle_recordset.php');
 
 /**
  * pgsql specific moodle recordset class
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Petr Skoda (http://skodak.org)
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
@@ -82,7 +78,7 @@ class pgsql_native_moodle_recordset extends moodle_recordset {
     }
 
     public function key() {
-    /// return first column value as key
+        // return first column value as key
         if (!$this->current) {
             return false;
         }
diff --git a/lib/dml/pgsql_native_moodle_temptables.php b/lib/dml/pgsql_native_moodle_temptables.php
index 4227da15cf9..cd87ef2e27c 100644
--- a/lib/dml/pgsql_native_moodle_temptables.php
+++ b/lib/dml/pgsql_native_moodle_temptables.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -20,15 +19,14 @@
  * are named differently than normal tables. Also used to be able to retrieve
  * temp table names included in the get_tables() method of the DB.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2010 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_temptables.php');
+require_once(__DIR__.'/moodle_temptables.php');
 
 class pgsql_native_moodle_temptables extends moodle_temptables {
     // I love these classes :-P
diff --git a/lib/dml/sqlite3_pdo_moodle_database.php b/lib/dml/sqlite3_pdo_moodle_database.php
index c52b2f1916a..e7410a5d50d 100644
--- a/lib/dml/sqlite3_pdo_moodle_database.php
+++ b/lib/dml/sqlite3_pdo_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -15,25 +14,22 @@
 // You should have received a copy of the GNU General Public License
 // along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
-
 /**
  * Experimental pdo database class.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Andrei Bautu
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/pdo_moodle_database.php');
+require_once(__DIR__.'/pdo_moodle_database.php');
 
 /**
  * Experimental pdo database class
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2008 Andrei Bautu
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
diff --git a/lib/dml/sqlsrv_native_moodle_database.php b/lib/dml/sqlsrv_native_moodle_database.php
index 90ec10479e5..168c68234c0 100644
--- a/lib/dml/sqlsrv_native_moodle_database.php
+++ b/lib/dml/sqlsrv_native_moodle_database.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -18,23 +17,21 @@
 /**
  * Native sqlsrv class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_database.php');
-require_once($CFG->libdir.'/dml/sqlsrv_native_moodle_recordset.php');
-require_once($CFG->libdir.'/dml/sqlsrv_native_moodle_temptables.php');
+require_once(__DIR__.'/moodle_database.php');
+require_once(__DIR__.'/sqlsrv_native_moodle_recordset.php');
+require_once(__DIR__.'/sqlsrv_native_moodle_temptables.php');
 
 /**
  * Native sqlsrv class representing moodle database interface.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
  */
@@ -331,29 +328,32 @@ class sqlsrv_native_moodle_database extends moodle_database {
         return $errorMessage;
     }
 
-    /***
-     * Bound variables *are* supported. Until I can get it to work, emulate the bindings
-     * The challenge/problem/bug is that although they work, doing a SELECT SCOPE_IDENTITY()
-     * doesn't return a value (no result set)
-     */
-
     /**
      * Prepare the query binding and do the actual query.
      *
      * @param string $sql The sql statement
-     * @param mixed $params array of params for binding. If NULL, they are ignored.
-     * @param mixed $sql_query_type - Type of operation
-     * @param mixed $free_result - Default true, transaction query will be freed.
-     * @param mixed $scrollable - Default false, to use for quickly seeking to target records
+     * @param array $params array of params for binding. If NULL, they are ignored.
+     * @param int $sql_query_type - Type of operation
+     * @param bool $free_result - Default true, transaction query will be freed.
+     * @param bool $scrollable - Default false, to use for quickly seeking to target records
+     * @return resource|bool result
      */
     private function do_query($sql, $params, $sql_query_type, $free_result = true, $scrollable = false) {
         list($sql, $params, $type) = $this->fix_sql_params($sql, $params);
 
+        /*
+         * Bound variables *are* supported. Until I can get it to work, emulate the bindings
+         * The challenge/problem/bug is that although they work, doing a SELECT SCOPE_IDENTITY()
+         * doesn't return a value (no result set)
+         *
+         * -- somebody from MS
+         */
+
         $sql = $this->emulate_bound_params($sql, $params);
         $this->query_start($sql, $params, $sql_query_type);
         if (!$scrollable) { // Only supporting next row
             $result = sqlsrv_query($this->sqlsrv, $sql);
-        } else { // Suporting absolute/relative rows
+        } else { // Supporting absolute/relative rows
             $result = sqlsrv_query($this->sqlsrv, $sql, array(), array('Scrollable' => SQLSRV_CURSOR_STATIC));
         }
 
@@ -575,7 +575,7 @@ class sqlsrv_native_moodle_database extends moodle_database {
     protected function normalise_value($column, $value) {
         $this->detect_objects($value);
 
-        if (is_bool($value)) {                               /// Always, convert boolean to int
+        if (is_bool($value)) {                               // Always, convert boolean to int
             $value = (int)$value;
         }                                                    // And continue processing because text columns with numeric info need special handling below
 
@@ -585,9 +585,9 @@ class sqlsrv_native_moodle_database extends moodle_database {
                 $value = unpack('H*hex', $value); // we leave it as array, so emulate_bound_params() can detect it
             }                                                // easily and "bind" the param ok.
 
-        } else if ($column->meta_type == 'X') {             // sqlsrv doesn't cast from int to text, so if text column
+        } else if ($column->meta_type == 'X') {              // sqlsrv doesn't cast from int to text, so if text column
             if (is_numeric($value)) { // and is numeric value then cast to string
-                $value = array('numstr' => (string)$value); // and put into array, so emulate_bound_params() will know how
+                $value = array('numstr' => (string)$value);  // and put into array, so emulate_bound_params() will know how
             }                                                // to "bind" the param ok, avoiding reverse conversion to number
         } else if ($value === '') {
 
@@ -602,6 +602,7 @@ class sqlsrv_native_moodle_database extends moodle_database {
      * Selectively call sqlsrv_free_stmt(), avoiding some warnings without using the horrible @
      *
      * @param sqlsrv_resource $resource resource to be freed if possible
+     * @return bool
      */
     private function free_result($resource) {
         if (!is_bool($resource)) { // true/false resources cannot be freed
@@ -688,7 +689,6 @@ class sqlsrv_native_moodle_database extends moodle_database {
         return null;
     }
 
-
     /**
      * Workaround for SQL*Server Native driver similar to MSSQL driver for
      * consistent behavior.
@@ -698,7 +698,7 @@ class sqlsrv_native_moodle_database extends moodle_database {
         if (empty($params)) {
             return $sql;
         }
-        /// ok, we have verified sql statement with ? and correct number of params
+        // ok, we have verified sql statement with ? and correct number of params
         $parts = explode('?', $sql);
         $return = array_shift($parts);
         foreach ($params as $param) {
@@ -1099,7 +1099,7 @@ class sqlsrv_native_moodle_database extends moodle_database {
         // convert params to ? types
         list($select, $params, $type) = $this->fix_sql_params($select, $params);
 
-        /// Get column metadata
+        // Get column metadata
         $columns = $this->get_columns($table);
         $column = $columns[$newfield];
 
@@ -1141,8 +1141,6 @@ class sqlsrv_native_moodle_database extends moodle_database {
     }
 
 
-    /// SQL helper functions
-
     public function sql_cast_char2int($fieldname, $text = false) {
         if (!$text) {
             return ' CAST(' . $fieldname . ' AS INT) ';
@@ -1300,8 +1298,6 @@ class sqlsrv_native_moodle_database extends moodle_database {
         }
     }
 
-    /// session locking
-
     public function session_lock_supported() {
         return true;
     }
@@ -1310,7 +1306,7 @@ class sqlsrv_native_moodle_database extends moodle_database {
      * Obtain session lock
      * @param int $rowid id of the row with session record
      * @param int $timeout max allowed time to wait for the lock in seconds
-     * @return bool success
+     * @return void
      */
     public function get_session_lock($rowid, $timeout) {
         if (!$this->session_lock_supported()) {
@@ -1361,14 +1357,6 @@ class sqlsrv_native_moodle_database extends moodle_database {
         $this->free_result($result);
     }
 
-
-    /// transactions
-
-    // NOTE:
-    // TODO -- should these be wrapped in query start/end? They arn't a query
-    // but information and error capture is nice. msk
-
-
     /**
      * Driver specific start of real database transaction,
      * this can not be used directly in code.
diff --git a/lib/dml/sqlsrv_native_moodle_recordset.php b/lib/dml/sqlsrv_native_moodle_recordset.php
index 1f9965506cb..6ca88aad323 100644
--- a/lib/dml/sqlsrv_native_moodle_recordset.php
+++ b/lib/dml/sqlsrv_native_moodle_recordset.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -18,15 +17,14 @@
 /**
  * sqlsrv specific recordset.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/moodle_recordset.php');
+require_once(__DIR__.'/moodle_recordset.php');
 
 class sqlsrv_native_moodle_recordset extends moodle_recordset {
 
@@ -55,7 +53,7 @@ class sqlsrv_native_moodle_recordset extends moodle_recordset {
     }
 
     public function key() {
-    /// return first column value as key
+        // return first column value as key
         if (!$this->current) {
             return false;
         }
diff --git a/lib/dml/sqlsrv_native_moodle_temptables.php b/lib/dml/sqlsrv_native_moodle_temptables.php
index fe860346586..2d9cc62b9c7 100644
--- a/lib/dml/sqlsrv_native_moodle_temptables.php
+++ b/lib/dml/sqlsrv_native_moodle_temptables.php
@@ -1,5 +1,4 @@
 <?php
-
 // This file is part of Moodle - http://moodle.org/
 //
 // Moodle is free software: you can redistribute it and/or modify
@@ -20,22 +19,20 @@
  * are named differently than normal tables. Also used to be able to retrieve
  * temp table names included in the get_tables() method of the DB.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
  */
 
 defined('MOODLE_INTERNAL') || die();
 
-require_once($CFG->libdir.'/dml/mssql_native_moodle_temptables.php');
+require_once(__DIR__.'/mssql_native_moodle_temptables.php');
 
-/***
+/**
  * This class is not specific to the SQL Server Native Driver but rather
  * to the family of Microsoft SQL Servers.
  *
- * @package    core
- * @subpackage dml_driver
+ * @package    core_dml
  * @copyright  2009 onwards Eloy Lafuente (stronk7) {@link http://stronk7.com}
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v2 or later
  */
diff --git a/lib/dml/tests/dml_test.php b/lib/dml/tests/dml_test.php
index 410c7ffef3b..4993d3596bb 100644
--- a/lib/dml/tests/dml_test.php
+++ b/lib/dml/tests/dml_test.php
@@ -17,8 +17,7 @@
 /**
  * DML layer tests
  *
- * @package    core
- * @subpackage dml
+ * @package    core_dml
  * @category   phpunit
  * @copyright  2008 Nicolas Connault
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@@ -63,8 +62,6 @@ class dml_testcase extends database_driver_testcase {
         return $debuginfo;
     }
 
-    // NOTE: please keep order of test methods here matching the order of moodle_database class methods
-
     function test_diagnose() {
         $DB = $this->tdb;
         $result = $DB->diagnose();
@@ -1090,7 +1087,7 @@ class dml_testcase extends database_driver_testcase {
         $this->assertEquals(3, $counter);
         $rs->close();
 
-        $rs = $DB->get_recordset_list($tablename, 'course',array()); /// Must return 0 rows without conditions. MDL-17645
+        $rs = $DB->get_recordset_list($tablename, 'course',array()); // Must return 0 rows without conditions. MDL-17645
 
         $counter = 0;
         foreach ($rs as $record) {
@@ -1316,7 +1313,7 @@ class dml_testcase extends database_driver_testcase {
         $this->assertEquals(2, next($records)->id);
         $this->assertEquals(4, next($records)->id);
 
-        $this->assertSame(array(), $records = $DB->get_records_list($tablename, 'course', array())); /// Must return 0 rows without conditions. MDL-17645
+        $this->assertSame(array(), $records = $DB->get_records_list($tablename, 'course', array())); // Must return 0 rows without conditions. MDL-17645
         $this->assertEquals(0, count($records));
 
         // note: delegate limits testing to test_get_records_sql()
@@ -3070,7 +3067,7 @@ class dml_testcase extends database_driver_testcase {
         $this->assertTrue($DB->delete_records_list($tablename, 'course', array(2, 3)));
         $this->assertEquals(1, $DB->count_records($tablename));
 
-        $this->assertTrue($DB->delete_records_list($tablename, 'course', array())); /// Must delete 0 rows without conditions. MDL-17645
+        $this->assertTrue($DB->delete_records_list($tablename, 'course', array())); // Must delete 0 rows without conditions. MDL-17645
         $this->assertEquals(1, $DB->count_records($tablename));
     }
 
@@ -3560,13 +3557,13 @@ class dml_testcase extends database_driver_testcase {
     function test_coalesce() {
         $DB = $this->tdb;
 
-        // Testing not-null ocurrences, return 1st
+        // Testing not-null occurrences, return 1st
         $sql = "SELECT COALESCE('returnthis', 'orthis', 'orwhynotthis') AS test" . $DB->sql_null_from_clause();
         $this->assertEquals('returnthis', $DB->get_field_sql($sql, array()));
         $sql = "SELECT COALESCE(:paramvalue, 'orthis', 'orwhynotthis') AS test" . $DB->sql_null_from_clause();
         $this->assertEquals('returnthis', $DB->get_field_sql($sql, array('paramvalue' => 'returnthis')));
 
-        // Testing null ocurrences, return 2nd
+        // Testing null occurrences, return 2nd
         $sql = "SELECT COALESCE(null, 'returnthis', 'orthis') AS test" . $DB->sql_null_from_clause();
         $this->assertEquals('returnthis', $DB->get_field_sql($sql, array()));
         $sql = "SELECT COALESCE(:paramvalue, 'returnthis', 'orthis') AS test" . $DB->sql_null_from_clause();
@@ -3574,7 +3571,7 @@ class dml_testcase extends database_driver_testcase {
         $sql = "SELECT COALESCE(null, :paramvalue, 'orthis') AS test" . $DB->sql_null_from_clause();
         $this->assertEquals('returnthis', $DB->get_field_sql($sql, array('paramvalue' => 'returnthis')));
 
-        // Testing null ocurrences, return 3rd
+        // Testing null occurrences, return 3rd
         $sql = "SELECT COALESCE(null, null, 'returnthis') AS test" . $DB->sql_null_from_clause();
         $this->assertEquals('returnthis', $DB->get_field_sql($sql, array()));
         $sql = "SELECT COALESCE(null, :paramvalue, 'returnthis') AS test" . $DB->sql_null_from_clause();
@@ -3582,7 +3579,7 @@ class dml_testcase extends database_driver_testcase {
         $sql = "SELECT COALESCE(null, null, :paramvalue) AS test" . $DB->sql_null_from_clause();
         $this->assertEquals('returnthis', $DB->get_field_sql($sql, array('paramvalue' => 'returnthis')));
 
-        // Testing all null ocurrences, return null
+        // Testing all null occurrences, return null
         // Note: under mssql, if all elements are nulls, at least one must be a "typed" null, hence
         // we cannot test this in a cross-db way easily, so next 2 tests are using
         // different queries depending of the DB family
@@ -3603,7 +3600,7 @@ class dml_testcase extends database_driver_testcase {
         $DB = $this->tdb;
         $dbman = $DB->get_manager();
 
-        /// Testing all sort of values
+        // Testing all sort of values
         $sql = "SELECT ".$DB->sql_concat("?", "?", "?")." AS fullname ". $DB->sql_null_from_clause();
         // string, some unicode chars
         $params = array('name', 'áéíóú', 'name3');
@@ -3621,7 +3618,7 @@ class dml_testcase extends database_driver_testcase {
         $params = array(123.45, null, 'test');
         $this->assertNull($DB->get_field_sql($sql, $params), 'ANSI behaviour: Concatenating NULL must return NULL - But in Oracle :-(. [%s]'); // Concatenate NULL with anything result = NULL
 
-        /// Testing fieldnames + values and also integer fieldnames
+        // Testing fieldnames + values and also integer fieldnames
         $table = $this->get_test_table();
         $tablename = $table->getName();
 
@@ -4328,7 +4325,7 @@ class dml_testcase extends database_driver_testcase {
         $DB2 = moodle_database::get_driver_instance($cfg->dbtype, $cfg->dblibrary);
         $DB2->connect($cfg->dbhost, $cfg->dbuser, $cfg->dbpass, $cfg->dbname, $cfg->prefix, $cfg->dboptions);
 
-        // Testing that acquiring a lock efectively locks
+        // Testing that acquiring a lock effectively locks
         // Get a session lock on connection1
         $rowid = rand(100, 200);
         $timeout = 1;
@@ -4337,14 +4334,14 @@ class dml_testcase extends database_driver_testcase {
         // Try to get the same session lock on connection2
         try {
             $DB2->get_session_lock($rowid, $timeout);
-            $DB2->release_session_lock($rowid); // Should not be excuted, but here for safety
+            $DB2->release_session_lock($rowid); // Should not be executed, but here for safety
             $this->fail('An Exception is missing, expected due to session lock acquired.');
         } catch (exception $e) {
             $this->assertTrue($e instanceof dml_sessionwait_exception);
             $DB->release_session_lock($rowid); // Release lock on connection1
         }
 
-        // Testing that releasing a lock efectively frees
+        // Testing that releasing a lock effectively frees
         // Get a session lock on connection1
         $rowid = rand(100, 200);
         $timeout = 1;
@@ -4613,7 +4610,7 @@ class moodle_database_for_testing extends moodle_database {
 
 
 /**
- * Dumb test class with toString() returrning 1.
+ * Dumb test class with toString() returning 1.
  */
 class dml_test_object_one {
     public function __toString() {