diff --git a/system/database/drivers/cubrid/cubrid_driver.php b/system/database/drivers/cubrid/cubrid_driver.php
index 42f08fb..99b8e00 100644
--- a/system/database/drivers/cubrid/cubrid_driver.php
+++ b/system/database/drivers/cubrid/cubrid_driver.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -21,12 +21,10 @@
  * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
- * @since		Version 2.0.2
+ * @since		Version 2.1
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * CUBRID Database Adapter Class
  *
@@ -42,79 +40,102 @@
  */
 class CI_DB_cubrid_driver extends CI_DB {
 
-	// Default CUBRID Broker port. Will be used unless user
-	// explicitly specifies another one.
-	const DEFAULT_PORT = 33000;
-
-	var $dbdriver = 'cubrid';
+	public $dbdriver = 'cubrid';
 
 	// The character used for escaping - no need in CUBRID
-	var	$_escape_char = '';
+	protected $_escape_char = '`';
 
 	// clause and character used for LIKE escape sequences - not used in CUBRID
-	var $_like_escape_str = '';
-	var $_like_escape_chr = '';
+	protected $_like_escape_str = '';
+	protected $_like_escape_chr = '';
 
 	/**
 	 * The syntax to count rows is slightly different across different
 	 * database engines, so this string appears in each driver and is
 	 * used for the count_all() and count_all_results() functions.
 	 */
-	var $_count_string = 'SELECT COUNT(*) AS ';
-	var $_random_keyword = ' RAND()'; // database specific random keyword
+	protected $_count_string = 'SELECT COUNT(*) AS ';
+	protected $_random_keyword = ' RAND()'; // database specific random keyword
+
+	// CUBRID-specific properties
+	public $auto_commit = TRUE;
+
+	public function __construct($params)
+	{
+		parent::__construct($params);
+
+		if (preg_match('/^CUBRID:[^:]+(:[0-9][1-9]{0,4})?:[^:]+:[^:]*:[^:]*:(\?.+)?$/', $this->dsn, $matches))
+		{
+			if (stripos($matches[2], 'autocommit=off') !== FALSE)
+			{
+				$this->auto_commit = FALSE;
+			}
+		}
+		else
+		{
+			// If no port is defined by the user, use the default value
+			$this->port == '' OR $this->port = 33000;
+		}
+	}
 
 	/**
 	 * Non-persistent database connection
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_connect()
+	public function db_connect()
 	{
-		// If no port is defined by the user, use the default value
-		if ($this->port == '')
-		{
-			$this->port = self::DEFAULT_PORT;
-		}
-
-		$conn = cubrid_connect($this->hostname, $this->port, $this->database, $this->username, $this->password);
-
-		if ($conn)
-		{
-			// Check if a user wants to run queries in dry, i.e. run the
-			// queries but not commit them.
-			if (isset($this->auto_commit) && ! $this->auto_commit)
-			{
-				cubrid_set_autocommit($conn, CUBRID_AUTOCOMMIT_FALSE);
-			}
-			else
-			{
-				cubrid_set_autocommit($conn, CUBRID_AUTOCOMMIT_TRUE);
-				$this->auto_commit = TRUE;
-			}
-		}
-
-		return $conn;
+		return $this->_cubrid_connect();
 	}
 
 	// --------------------------------------------------------------------
 
 	/**
 	 * Persistent database connection
+	 *
 	 * In CUBRID persistent DB connection is supported natively in CUBRID
 	 * engine which can be configured in the CUBRID Broker configuration
 	 * file by setting the CCI_PCONNECT parameter to ON. In that case, all
 	 * connections established between the client application and the
-	 * server will become persistent. This is calling the same
-	 * @cubrid_connect function will establish persisten connection
-	 * considering that the CCI_PCONNECT is ON.
+	 * server will become persistent.
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_pconnect()
+	public function db_pconnect()
 	{
-		return $this->db_connect();
+		return $this->_cubrid_connect(TRUE);
+	}
+
+	// --------------------------------------------------------------------
+
+	/**
+	 * CUBRID connection
+	 *
+	 * A CUBRID-specific method to create a connection to the database.
+	 * Except for determining if a persistent connection should be used,
+	 * the rest of the logic is the same for db_connect() and db_pconnect().
+	 *
+	 * @param	bool
+	 * @return	resource
+	 */
+	protected function _cubrid_connect($persistent = FALSE)
+	{
+		if (preg_match('/^CUBRID:[^:]+(:[0-9][1-9]{0,4})?:[^:]+:([^:]*):([^:]*):(\?.+)?$/', $this->dsn, $matches))
+		{
+			$_temp = ($persistent !== TRUE) ? 'cubrid_connect_with_url' : 'cubrid_pconnect_with_url';
+			$conn_id = ($matches[2] === '' && $matches[3] === '' && $this->username !== '' && $this->password !== '')
+					? $_temp($this->dsn, $this->username, $this->password)
+					: $_temp($this->dsn);
+		}
+		else
+		{
+			$_temp = ($persistent !== TRUE) ? 'cubrid_connect' : 'cubrid_pconnect';
+			$conn_id = ($this->username !== '')
+					? $_temp($this->hostname, $this->port, $this->database, $this->username, $this->password)
+					: $_temp($this->hostname, $this->port, $this->database);
+		}
+
+		return $conn_id;
 	}
 
 	// --------------------------------------------------------------------
@@ -125,10 +146,9 @@
 	 * Keep / reestablish the db connection if no queries have been
 	 * sent for a length of time exceeding the server's idle timeout
 	 *
-	 * @access	public
 	 * @return	void
 	 */
-	function reconnect()
+	public function reconnect()
 	{
 		if (cubrid_ping($this->conn_id) === FALSE)
 		{
@@ -141,10 +161,9 @@
 	/**
 	 * Select the database
 	 *
-	 * @access	private called by the base class
 	 * @return	resource
 	 */
-	function db_select()
+	public function db_select()
 	{
 		// In CUBRID there is no need to select a database as the database
 		// is chosen at the connection time.
@@ -158,16 +177,10 @@
 	/**
 	 * Version number query string
 	 *
-	 * @access	public
 	 * @return	string
 	 */
-	function _version()
+	protected function _version()
 	{
-		// To obtain the CUBRID Server version, no need to run the SQL query.
-		// CUBRID PHP API provides a function to determin this value.
-		// This is why we also need to add 'cubrid' value to the list of
-		// $driver_version_exceptions array in DB_driver class in
-		// version() function.
 		return cubrid_get_server_info($this->conn_id);
 	}
 
@@ -176,14 +189,12 @@
 	/**
 	 * Execute the query
 	 *
-	 * @access	private called by the base class
 	 * @param	string	an SQL query
 	 * @return	resource
 	 */
-	function _execute($sql)
+	protected function _execute($sql)
 	{
-		$sql = $this->_prep_query($sql);
-		return @cubrid_query($sql, $this->conn_id);
+		return @cubrid_query($this->_prep_query($sql), $this->conn_id);
 	}
 
 	// --------------------------------------------------------------------
@@ -193,13 +204,11 @@
 	 *
 	 * If needed, each database adapter can prep the query string
 	 *
-	 * @access	private called by execute()
 	 * @param	string	an SQL query
 	 * @return	string
 	 */
-	function _prep_query($sql)
+	protected function _prep_query($sql)
 	{
-		// No need to prepare
 		return $sql;
 	}
 
@@ -208,18 +217,12 @@
 	/**
 	 * Begin Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_begin($test_mode = FALSE)
+	public function trans_begin($test_mode = FALSE)
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -227,7 +230,7 @@
 		// Reset the transaction failure flag.
 		// If the $test_mode flag is set to TRUE transactions will be rolled back
 		// even if the queries produce a successful result.
-		$this->_trans_failure = ($test_mode === TRUE) ? TRUE : FALSE;
+		$this->_trans_failure = ($test_mode === TRUE);
 
 		if (cubrid_get_autocommit($this->conn_id))
 		{
@@ -242,18 +245,12 @@
 	/**
 	 * Commit Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_commit()
+	public function trans_commit()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -273,18 +270,12 @@
 	/**
 	 * Rollback Transaction
 	 *
-	 * @access	public
 	 * @return	bool
 	 */
-	function trans_rollback()
+	public function trans_rollback()
 	{
-		if ( ! $this->trans_enabled)
-		{
-			return TRUE;
-		}
-
 		// When transactions are nested we only begin/commit/rollback the outermost ones
-		if ($this->_trans_depth > 0)
+		if ( ! $this->trans_enabled OR $this->_trans_depth > 0)
 		{
 			return TRUE;
 		}
@@ -304,12 +295,11 @@
 	/**
 	 * Escape String
 	 *
-	 * @access	public
 	 * @param	string
 	 * @param	bool	whether or not the string will be used in a LIKE condition
 	 * @return	string
 	 */
-	function escape_str($str, $like = FALSE)
+	public function escape_str($str, $like = FALSE)
 	{
 		if (is_array($str))
 		{
@@ -321,7 +311,9 @@
 			return $str;
 		}
 
-		if (function_exists('cubrid_real_escape_string') AND is_resource($this->conn_id))
+		if (function_exists('cubrid_real_escape_string') &&
+			(is_resource($this->conn_id)
+				OR (get_resource_type($this->conn_id) === 'Unknown' && preg_match('/Resource id #/', strval($this->conn_id)))))
 		{
 			$str = cubrid_real_escape_string($str, $this->conn_id);
 		}
@@ -333,7 +325,7 @@
 		// escape LIKE condition wildcards
 		if ($like === TRUE)
 		{
-			$str = str_replace(array('%', '_'), array('\\%', '\\_'), $str);
+			return str_replace(array('%', '_'), array('\\%', '\\_'), $str);
 		}
 
 		return $str;
@@ -356,10 +348,9 @@
 	/**
 	 * Insert ID
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function insert_id()
+	public function insert_id()
 	{
 		return @cubrid_insert_id($this->conn_id);
 	}
@@ -372,27 +363,24 @@
 	 * Generates a platform-specific query string that counts all records in
 	 * the specified table
 	 *
-	 * @access	public
 	 * @param	string
-	 * @return	string
+	 * @return	int
 	 */
-	function count_all($table = '')
+	public function count_all($table = '')
 	{
 		if ($table == '')
 		{
 			return 0;
 		}
-		
-		$query = $this->query($this->_count_string . $this->_protect_identifiers('numrows') . " FROM " . $this->_protect_identifiers($table, TRUE, NULL, FALSE));
-
+		$query = $this->query($this->_count_string.$this->_protect_identifiers('numrows').' FROM '.$this->_protect_identifiers($table, TRUE, NULL, FALSE));
 		if ($query->num_rows() == 0)
 		{
 			return 0;
 		}
 
-		$row = $query->row();
+		$query = $query->row();
 		$this->_reset_select();
-		return (int) $row->numrows;
+		return (int) $query->numrows;
 	}
 
 	// --------------------------------------------------------------------
@@ -402,17 +390,16 @@
 	 *
 	 * Generates a platform-specific query string so that the table names can be fetched
 	 *
-	 * @access	private
-	 * @param	boolean
+	 * @param	bool
 	 * @return	string
 	 */
-	function _list_tables($prefix_limit = FALSE)
+	protected function _list_tables($prefix_limit = FALSE)
 	{
-		$sql = "SHOW TABLES";
+		$sql = 'SHOW TABLES';
 
-		if ($prefix_limit !== FALSE AND $this->dbprefix != '')
+		if ($prefix_limit !== FALSE && $this->dbprefix != '')
 		{
-			$sql .= " LIKE '".$this->escape_like_str($this->dbprefix)."%'";
+			return $sql." LIKE '".$this->escape_like_str($this->dbprefix)."%'";
 		}
 
 		return $sql;
@@ -425,13 +412,12 @@
 	 *
 	 * Generates a platform-specific query string so that the column names can be fetched
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _list_columns($table = '')
+	protected function _list_columns($table = '')
 	{
-		return "SHOW COLUMNS FROM ".$this->_protect_identifiers($table, TRUE, NULL, FALSE);
+		return 'SHOW COLUMNS FROM '.$this->_protect_identifiers($table, TRUE, NULL, FALSE);
 	}
 
 	// --------------------------------------------------------------------
@@ -441,13 +427,12 @@
 	 *
 	 * Generates a platform-specific query so that the column data can be retrieved
 	 *
-	 * @access	public
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	string
 	 */
-	function _field_data($table)
+	protected function _field_data($table)
 	{
-		return "SELECT * FROM ".$table." LIMIT 1";
+		return 'SELECT * FROM '.$table.' LIMIT 1';
 	}
 
 	// --------------------------------------------------------------------
@@ -455,10 +440,9 @@
 	/**
 	 * The error message string
 	 *
-	 * @access	private
 	 * @return	string
 	 */
-	function _error_message()
+	protected function _error_message()
 	{
 		return cubrid_error($this->conn_id);
 	}
@@ -468,10 +452,9 @@
 	/**
 	 * The error message number
 	 *
-	 * @access	private
-	 * @return	integer
+	 * @return	int
 	 */
-	function _error_number()
+	protected function _error_number()
 	{
 		return cubrid_errno($this->conn_id);
 	}
@@ -483,11 +466,10 @@
 	 *
 	 * This function escapes column and table names
 	 *
-	 * @access	private
 	 * @param	string
 	 * @return	string
 	 */
-	function _escape_identifiers($item)
+	public function _escape_identifiers($item)
 	{
 		if ($this->_escape_char == '')
 		{
@@ -498,24 +480,20 @@
 		{
 			if (strpos($item, '.'.$id) !== FALSE)
 			{
-				$str = $this->_escape_char. str_replace('.', $this->_escape_char.'.', $item);
+				$item = str_replace('.', $this->_escape_char.'.', $item);
 
 				// remove duplicates if the user already included the escape
-				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+				return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item);
 			}
 		}
 
 		if (strpos($item, '.') !== FALSE)
 		{
-			$str = $this->_escape_char.str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item).$this->_escape_char;
-		}
-		else
-		{
-			$str = $this->_escape_char.$item.$this->_escape_char;
+			$item = str_replace('.', $this->_escape_char.'.'.$this->_escape_char, $item);
 		}
 
 		// remove duplicates if the user already included the escape
-		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $str);
+		return preg_replace('/['.$this->_escape_char.']+/', $this->_escape_char, $this->_escape_char.$item.$this->_escape_char);
 	}
 
 	// --------------------------------------------------------------------
@@ -526,11 +504,10 @@
 	 * This function implicitly groups FROM tables so there is no confusion
 	 * about operator precedence in harmony with SQL standards
 	 *
-	 * @access	public
-	 * @param	type
-	 * @return	type
+	 * @param	string	the table name
+	 * @return	string
 	 */
-	function _from_tables($tables)
+	protected function _from_tables($tables)
 	{
 		if ( ! is_array($tables))
 		{
@@ -547,15 +524,14 @@
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	function _insert($table, $keys, $values)
+	protected function _insert($table, $keys, $values)
 	{
-		return "INSERT INTO ".$table." (\"".implode('", "', $keys)."\") VALUES (".implode(', ', $values).")";
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -566,15 +542,14 @@
 	 *
 	 * Generates a platform-specific replace string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	function _replace($table, $keys, $values)
+	protected function _replace($table, $keys, $values)
 	{
-		return "REPLACE INTO ".$table." (\"".implode('", "', $keys)."\") VALUES (".implode(', ', $values).")";
+		return 'REPLACE INTO '.$table.' ('.implode(', ', $keys).') VALUES ('.implode(', ', $values).')';
 	}
 
 	// --------------------------------------------------------------------
@@ -584,26 +559,23 @@
 	 *
 	 * Generates a platform-specific insert string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the insert keys
 	 * @param	array	the insert values
 	 * @return	string
 	 */
-	function _insert_batch($table, $keys, $values)
+	protected function _insert_batch($table, $keys, $values)
 	{
-		return "INSERT INTO ".$table." (\"".implode('", "', $keys)."\") VALUES ".implode(', ', $values);
+		return 'INSERT INTO '.$table.' ('.implode(', ', $keys).') VALUES '.implode(', ', $values);
 	}
 
 	// --------------------------------------------------------------------
 
-
 	/**
 	 * Update statement
 	 *
 	 * Generates a platform-specific update string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
@@ -611,24 +583,22 @@
 	 * @param	array	the limit clause
 	 * @return	string
 	 */
-	function _update($table, $values, $where, $orderby = array(), $limit = FALSE)
+	protected function _update($table, $values, $where, $orderby = array(), $limit = FALSE, $like = array())
 	{
 		foreach ($values as $key => $val)
 		{
-			$valstr[] = sprintf('"%s" = %s', $key, $val);
+			$valstr[] = $key.' = '.$val;
 		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
+		$where = ($where != '' && count($where) > 0) ? ' WHERE '.implode(' ', $where) : '';
+		if (count($like) > 0)
+		{
+			$where .= ($where === '' ? ' WHERE ' : ' AND ').implode(' ', $like);
+		}
 
-		$orderby = (count($orderby) >= 1)?' ORDER BY '.implode(", ", $orderby):'';
-
-		$sql = "UPDATE ".$table." SET ".implode(', ', $valstr);
-
-		$sql .= ($where != '' AND count($where) >=1) ? " WHERE ".implode(" ", $where) : '';
-
-		$sql .= $orderby.$limit;
-
-		return $sql;
+		return 'UPDATE '.$table.' SET '.implode(', ', $valstr).$where
+			.(count($orderby) > 0 ? ' ORDER BY '.implode(', ', $orderby) : '')
+			.( ! $limit ? '' : ' LIMIT '.$limit);
 	}
 
 	// --------------------------------------------------------------------
@@ -639,17 +609,14 @@
 	 *
 	 * Generates a platform-specific batch update string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the update data
 	 * @param	array	the where clause
 	 * @return	string
 	 */
-	function _update_batch($table, $values, $index, $where = NULL)
+	protected function _update_batch($table, $values, $index, $where = NULL)
 	{
 		$ids = array();
-		$where = ($where != '' AND count($where) >=1) ? implode(" ", $where).' AND ' : '';
-
 		foreach ($values as $key => $val)
 		{
 			$ids[] = $val[$index];
@@ -663,30 +630,21 @@
 			}
 		}
 
-		$sql = "UPDATE ".$table." SET ";
 		$cases = '';
-
 		foreach ($final as $k => $v)
 		{
-			$cases .= $k.' = CASE '."\n";
-			foreach ($v as $row)
-			{
-				$cases .= $row."\n";
-			}
-
-			$cases .= 'ELSE '.$k.' END, ';
+			$cases .= $k." = CASE \n"
+				.implode("\n", $v)
+				.'ELSE '.$k.' END, ';
 		}
 
-		$sql .= substr($cases, 0, -2);
-
-		$sql .= ' WHERE '.$where.$index.' IN ('.implode(',', $ids).')';
-
-		return $sql;
+		return 'UPDATE '.$table.' SET '.substr($cases, 0, -2)
+			.' WHERE '.(($where != '' && count($where) > 0) ? implode(' ', $where).' AND ' : '')
+			.$index.' IN ('.implode(',', $ids).')';
 	}
 
 	// --------------------------------------------------------------------
 
-
 	/**
 	 * Truncate statement
 	 *
@@ -694,13 +652,12 @@
 	 * If the database does not support the truncate() command
 	 * This function maps to "DELETE FROM table"
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @return	string
 	 */
-	function _truncate($table)
+	protected function _truncate($table)
 	{
-		return "TRUNCATE ".$table;
+		return 'TRUNCATE '.$table;
 	}
 
 	// --------------------------------------------------------------------
@@ -710,31 +667,23 @@
 	 *
 	 * Generates a platform-specific delete string from the supplied data
 	 *
-	 * @access	public
 	 * @param	string	the table name
 	 * @param	array	the where clause
 	 * @param	string	the limit clause
 	 * @return	string
 	 */
-	function _delete($table, $where = array(), $like = array(), $limit = FALSE)
+	protected function _delete($table, $where = array(), $like = array(), $limit = FALSE)
 	{
 		$conditions = '';
 
 		if (count($where) > 0 OR count($like) > 0)
 		{
-			$conditions = "\nWHERE ";
-			$conditions .= implode("\n", $this->ar_where);
-
-			if (count($where) > 0 && count($like) > 0)
-			{
-				$conditions .= " AND ";
-			}
-			$conditions .= implode("\n", $like);
+			$conditions = "\nWHERE ".implode("\n", $where)
+					.((count($where) > 0 && count($like) > 0) ? ' AND ' : '')
+					.implode("\n", $like);
 		}
 
-		$limit = ( ! $limit) ? '' : ' LIMIT '.$limit;
-
-		return "DELETE FROM ".$table.$conditions.$limit;
+		return 'DELETE FROM '.$table.$conditions.( ! $limit ? '' : ' LIMIT '.$limit);
 	}
 
 	// --------------------------------------------------------------------
@@ -744,24 +693,14 @@
 	 *
 	 * Generates a platform-specific LIMIT clause
 	 *
-	 * @access	public
 	 * @param	string	the sql query string
-	 * @param	integer	the number of rows to limit the query to
-	 * @param	integer	the offset value
+	 * @param	int	the number of rows to limit the query to
+	 * @param	int	the offset value
 	 * @return	string
 	 */
-	function _limit($sql, $limit, $offset)
+	protected function _limit($sql, $limit, $offset)
 	{
-		if ($offset == 0)
-		{
-			$offset = '';
-		}
-		else
-		{
-			$offset .= ", ";
-		}
-
-		return $sql."LIMIT ".$offset.$limit;
+		return $sql.'LIMIT '.($offset == 0 ? '' : $offset.', ').$limit;
 	}
 
 	// --------------------------------------------------------------------
@@ -769,17 +708,15 @@
 	/**
 	 * Close DB Connection
 	 *
-	 * @access	public
 	 * @param	resource
 	 * @return	void
 	 */
-	function _close($conn_id)
+	protected function _close($conn_id)
 	{
 		@cubrid_close($conn_id);
 	}
 
 }
 
-
 /* End of file cubrid_driver.php */
 /* Location: ./system/database/drivers/cubrid/cubrid_driver.php */
diff --git a/system/database/drivers/cubrid/cubrid_forge.php b/system/database/drivers/cubrid/cubrid_forge.php
index 85e7400..048a059 100644
--- a/system/database/drivers/cubrid/cubrid_forge.php
+++ b/system/database/drivers/cubrid/cubrid_forge.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -21,12 +21,10 @@
  * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
- * @since		Version 1.0
+ * @since		Version 2.1
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * CUBRID Forge Class
  *
@@ -39,14 +37,13 @@
 	/**
 	 * Create database
 	 *
-	 * @access	private
 	 * @param	string	the database name
 	 * @return	bool
 	 */
-	function _create_database($name)
+	public function _create_database($name)
 	{
-		// CUBRID does not allow to create a database in SQL. The GUI tools
-		// have to be used for this purpose.
+		// CUBRID does not allow to create a database in SQL. GUI or
+		// command line tools have to be used for this purpose.
 		return FALSE;
 	}
 
@@ -55,14 +52,13 @@
 	/**
 	 * Drop database
 	 *
-	 * @access	private
 	 * @param	string	the database name
 	 * @return	bool
 	 */
-	function _drop_database($name)
+	public function _drop_database($name)
 	{
-		// CUBRID does not allow to drop a database in SQL. The GUI tools
-		// have to be used for this purpose.
+		// CUBRID does not allow to drop a database in SQL. GUI or
+		// command line tools have to be used for this purpose.
 		return FALSE;
 	}
 
@@ -71,40 +67,35 @@
 	/**
 	 * Process Fields
 	 *
-	 * @access	private
 	 * @param	mixed	the fields
 	 * @return	string
 	 */
-	function _process_fields($fields)
+	protected function _process_fields($fields)
 	{
 		$current_field_count = 0;
 		$sql = '';
 
-		foreach ($fields as $field=>$attributes)
+		foreach ($fields as $field => $attributes)
 		{
 			// Numeric field names aren't allowed in databases, so if the key is
 			// numeric, we know it was assigned by PHP and the developer manually
 			// entered the field information, so we'll simply add it to the list
 			if (is_numeric($field))
 			{
-				$sql .= "\n\t$attributes";
+				$sql .= "\n\t".$attributes;
 			}
 			else
 			{
 				$attributes = array_change_key_case($attributes, CASE_UPPER);
 
-				$sql .= "\n\t\"" . $this->db->_protect_identifiers($field) . "\"";
+				$sql .= "\n\t".$this->db->protect_identifiers($field)
+					.( ! empty($attributes['NAME']) ? ' '.$this->db->protect_identifiers($attributes['NAME']).' ' : '');
 
-				if (array_key_exists('NAME', $attributes))
-				{
-					$sql .= ' '.$this->db->_protect_identifiers($attributes['NAME']).' ';
-				}
-
-				if (array_key_exists('TYPE', $attributes))
+				if ( ! empty($attributes['TYPE']))
 				{
 					$sql .= ' '.$attributes['TYPE'];
 
-					if (array_key_exists('CONSTRAINT', $attributes))
+					if ( ! empty($attributes['CONSTRAINT']))
 					{
 						switch ($attributes['TYPE'])
 						{
@@ -113,9 +104,10 @@
 							case 'numeric':
 								$sql .= '('.implode(',', $attributes['CONSTRAINT']).')';
 								break;
-							case 'enum': 	// As of version 8.4.0 CUBRID does not support
-											// enum data type.
-											break;
+							case 'enum':
+								// Will be supported in the future as part a part of
+								// MySQL compatibility features.
+								break;
 							case 'set':
 								$sql .= '("'.implode('","', $attributes['CONSTRAINT']).'")';
 								break;
@@ -125,36 +117,19 @@
 					}
 				}
 
-				if (array_key_exists('UNSIGNED', $attributes) && $attributes['UNSIGNED'] === TRUE)
+			/* As of version 8.4.1 CUBRID does not support UNSIGNED INTEGER data type.
+			 * Will be supported in the next release as a part of MySQL Compatibility.
+			 *
+				if (isset($attributes['UNSIGNED']) && $attributes['UNSIGNED'] === TRUE)
 				{
-					//$sql .= ' UNSIGNED';
-					// As of version 8.4.0 CUBRID does not support UNSIGNED INTEGER data type.
-					// Will be supported in the next release as a part of MySQL Compatibility.
+					$sql .= ' UNSIGNED';
 				}
+			 */
 
-				if (array_key_exists('DEFAULT', $attributes))
-				{
-					$sql .= ' DEFAULT \''.$attributes['DEFAULT'].'\'';
-				}
-
-				if (array_key_exists('NULL', $attributes) && $attributes['NULL'] === TRUE)
-				{
-					$sql .= ' NULL';
-				}
-				else
-				{
-					$sql .= ' NOT NULL';
-				}
-
-				if (array_key_exists('AUTO_INCREMENT', $attributes) && $attributes['AUTO_INCREMENT'] === TRUE)
-				{
-					$sql .= ' AUTO_INCREMENT';
-				}
-
-				if (array_key_exists('UNIQUE', $attributes) && $attributes['UNIQUE'] === TRUE)
-				{
-					$sql .= ' UNIQUE';
-				}
+				$sql .= (isset($attributes['DEFAULT']) ? " DEFAULT '".$attributes['DEFAULT']."'" : '')
+					.(( ! empty($attributes['NULL']) && $attributes['NULL'] === TRUE) ? ' NULL' : ' NOT NULL')
+					.(( ! empty($attributes['AUTO_INCREMENT']) && $attributes['AUTO_INCREMENT'] === TRUE) ? ' AUTO_INCREMENT' : '')
+					.(( ! empty($attributes['UNIQUE']) && $attributes['UNIQUE'] === TRUE) ? ' UNIQUE' : '');
 			}
 
 			// don't add a comma on the end of the last field
@@ -172,7 +147,6 @@
 	/**
 	 * Create Table
 	 *
-	 * @access	private
 	 * @param	string	the table name
 	 * @param	mixed	the fields
 	 * @param	mixed	primary key(s)
@@ -180,28 +154,24 @@
 	 * @param	boolean	should 'IF NOT EXISTS' be added to the SQL
 	 * @return	bool
 	 */
-	function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
+	public function _create_table($table, $fields, $primary_keys, $keys, $if_not_exists)
 	{
 		$sql = 'CREATE TABLE ';
 
+		/* As of version 8.4.1 CUBRID does not support this SQL syntax.
 		if ($if_not_exists === TRUE)
 		{
-			//$sql .= 'IF NOT EXISTS ';
-			// As of version 8.4.0 CUBRID does not support this SQL syntax.
+			$sql .= 'IF NOT EXISTS ';
 		}
+		*/
 
-		$sql .= $this->db->_escape_identifiers($table)." (";
-
-		$sql .= $this->_process_fields($fields);
+		$sql .= $this->db->protect_identifiers($table).' ('.$this->_process_fields($fields);
 
 		// If there is a PK defined
 		if (count($primary_keys) > 0)
 		{
-			$key_name = "pk_" . $table . "_" .
-				$this->db->_protect_identifiers(implode('_', $primary_keys));
-			
-			$primary_keys = $this->db->_protect_identifiers($primary_keys);
-			$sql .= ",\n\tCONSTRAINT " . $key_name . " PRIMARY KEY(" . implode(', ', $primary_keys) . ")";
+			$key_name = $this->db->protect_identifiers('pk_'.$table.'_'.implode('_', $primary_keys));
+			$sql .= ",\n\tCONSTRAINT ".$key_name.' PRIMARY KEY('.implode(', ', $this->db->protect_identifiers($primary_keys)).')';
 		}
 
 		if (is_array($keys) && count($keys) > 0)
@@ -210,22 +180,20 @@
 			{
 				if (is_array($key))
 				{
-					$key_name = $this->db->_protect_identifiers(implode('_', $key));
-					$key = $this->db->_protect_identifiers($key);
+					$key_name = $this->db->protect_identifiers('idx_'.$table.implode('_', $key));
+					$key = $this->db->protect_identifiers($key);
 				}
 				else
 				{
-					$key_name = $this->db->_protect_identifiers($key);
+					$key_name = $this->db->protect_identifiers('idx_'.$table.$key);
 					$key = array($key_name);
 				}
-				
-				$sql .= ",\n\tKEY \"{$key_name}\" (" . implode(', ', $key) . ")";
+
+				$sql .= ",\n\tKEY ".$key_name.' ('.implode(', ', $key).')';
 			}
 		}
 
-		$sql .= "\n);";
-
-		return $sql;
+		return $sql."\n);";
 	}
 
 	// --------------------------------------------------------------------
@@ -233,12 +201,11 @@
 	/**
 	 * Drop Table
 	 *
-	 * @access	private
 	 * @return	string
 	 */
-	function _drop_table($table)
+	public function _drop_table($table)
 	{
-		return "DROP TABLE IF EXISTS ".$this->db->_escape_identifiers($table);
+		return 'DROP TABLE IF EXISTS '.$this->db->protect_identifiers($table);
 	}
 
 	// --------------------------------------------------------------------
@@ -249,31 +216,24 @@
 	 * Generates a platform-specific query so that a table can be altered
 	 * Called by add_column(), drop_column(), and column_alter(),
 	 *
-	 * @access	private
 	 * @param	string	the ALTER type (ADD, DROP, CHANGE)
 	 * @param	string	the column name
 	 * @param	array	fields
 	 * @param	string	the field after which we should add the new field
-	 * @return	object
+	 * @return	string
 	 */
-	function _alter_table($alter_type, $table, $fields, $after_field = '')
+	public function _alter_table($alter_type, $table, $fields, $after_field = '')
 	{
-		$sql = 'ALTER TABLE '.$this->db->_protect_identifiers($table)." $alter_type ";
+		$sql = 'ALTER TABLE '.$this->db->protect_identifiers($table).' '.$alter_type.' ';
 
 		// DROP has everything it needs now.
-		if ($alter_type == 'DROP')
+		if ($alter_type === 'DROP')
 		{
-			return $sql.$this->db->_protect_identifiers($fields);
+			return $sql.$this->db->protect_identifiers($fields);
 		}
 
-		$sql .= $this->_process_fields($fields);
-
-		if ($after_field != '')
-		{
-			$sql .= ' AFTER ' . $this->db->_protect_identifiers($after_field);
-		}
-
-		return $sql;
+		return $sql.$this->_process_fields($fields)
+			.($after_field != '' ? ' AFTER '.$this->db->protect_identifiers($after_field) : '');
 	}
 
 	// --------------------------------------------------------------------
@@ -283,18 +243,16 @@
 	 *
 	 * Generates a platform-specific query so that a table can be renamed
 	 *
-	 * @access	private
 	 * @param	string	the old table name
 	 * @param	string	the new table name
 	 * @return	string
 	 */
-	function _rename_table($table_name, $new_table_name)
+	public function _rename_table($table_name, $new_table_name)
 	{
-		$sql = 'RENAME TABLE '.$this->db->_protect_identifiers($table_name)." AS ".$this->db->_protect_identifiers($new_table_name);
-		return $sql;
+		return 'RENAME TABLE '.$this->db->protect_identifiers($table_name).' AS '.$this->db->protect_identifiers($new_table_name);
 	}
 
 }
 
 /* End of file cubrid_forge.php */
-/* Location: ./system/database/drivers/cubrid/cubrid_forge.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/cubrid/cubrid_forge.php */
diff --git a/system/database/drivers/cubrid/cubrid_result.php b/system/database/drivers/cubrid/cubrid_result.php
index 4c0fede..4539547 100644
--- a/system/database/drivers/cubrid/cubrid_result.php
+++ b/system/database/drivers/cubrid/cubrid_result.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -21,12 +21,10 @@
  * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
- * @since		Version 2.0.2
+ * @since		Version 2.1
  * @filesource
  */
 
-// --------------------------------------------------------------------
-
 /**
  * CUBRID Result Class
  *
@@ -41,10 +39,9 @@
 	/**
 	 * Number of rows in the result set
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function num_rows()
+	public function num_rows()
 	{
 		return @cubrid_num_rows($this->result_id);
 	}
@@ -54,10 +51,9 @@
 	/**
 	 * Number of fields in the result set
 	 *
-	 * @access	public
-	 * @return	integer
+	 * @return	int
 	 */
-	function num_fields()
+	public function num_fields()
 	{
 		return @cubrid_num_fields($this->result_id);
 	}
@@ -69,10 +65,9 @@
 	 *
 	 * Generates an array of column names
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function list_fields()
+	public function list_fields()
 	{
 		return cubrid_column_names($this->result_id);
 	}
@@ -84,59 +79,25 @@
 	 *
 	 * Generates an array of objects containing field meta-data
 	 *
-	 * @access	public
 	 * @return	array
 	 */
-	function field_data()
+	public function field_data()
 	{
 		$retval = array();
-
-		$tablePrimaryKeys = array();
+		$i = 0;
 
 		while ($field = cubrid_fetch_field($this->result_id))
 		{
-			$F				= new stdClass();
-			$F->name		= $field->name;
-			$F->type		= $field->type;
-			$F->default		= $field->def;
-			$F->max_length	= $field->max_length;
-
-			// At this moment primary_key property is not returned when
-			// cubrid_fetch_field is called. The following code will
-			// provide a patch for it. primary_key property will be added
-			// in the next release.
-
-			// TODO: later version of CUBRID will provide primary_key
-			// property.
-			// When PK is defined in CUBRID, an index is automatically
-			// created in the db_index system table in the form of
-			// pk_tblname_fieldname. So the following will count how many
-			// columns are there which satisfy this format.
-			// The query will search for exact single columns, thus
-			// compound PK is not supported.
-			$res = cubrid_query($this->conn_id,
-				"SELECT COUNT(*) FROM db_index WHERE class_name = '" . $field->table .
-				"' AND is_primary_key = 'YES' AND index_name = 'pk_" .
-				$field->table . "_" . $field->name . "'"
-			);
-
-			if ($res)
-			{
-				$row = cubrid_fetch_array($res, CUBRID_NUM);
-				$F->primary_key = ($row[0] > 0 ? 1 : null);
-			}
-			else
-			{
-				$F->primary_key = null;
-			}
-
-			if (is_resource($res))
-			{
-				cubrid_close_request($res);
-				$this->result_id = FALSE;
-			}
-
-			$retval[] = $F;
+			$retval[$i]			= new stdClass();
+			$retval[$i]->name		= $field->name;
+			// CUBRID returns type as e.g. varchar(100),
+			// so we need to remove all digits and brackets.
+			$retval[$i]->type		= preg_replace('/[\d()]/', '', $field->type);
+			$retval[$i]->default		= $field->def;
+			// Use CUBRID's native API to obtain column's max_length,
+			// otherwise $field->max_length has incorrect info
+			$retval[$i]->max_length		= cubrid_field_len($this->result_id, $i);
+			$retval[$i++]->primary_key	= $field->primary_key;
 		}
 
 		return $retval;
@@ -147,13 +108,12 @@
 	/**
 	 * Free the result
 	 *
-	 * @return	null
+	 * @return	void
 	 */
-	function free_result()
+	public function free_result()
 	{
-		if(is_resource($this->result_id) ||
-			get_resource_type($this->result_id) == "Unknown" &&
-			preg_match('/Resource id #/', strval($this->result_id)))
+		if (is_resource($this->result_id) OR
+			(get_resource_type($this->result_id) === 'Unknown' && preg_match('/Resource id #/', strval($this->result_id))))
 		{
 			cubrid_close_request($this->result_id);
 			$this->result_id = FALSE;
@@ -169,10 +129,9 @@
 	 * this internally before fetching results to make sure the
 	 * result set starts at zero
 	 *
-	 * @access	private
 	 * @return	array
 	 */
-	function _data_seek($n = 0)
+	protected function _data_seek($n = 0)
 	{
 		return cubrid_data_seek($this->result_id, $n);
 	}
@@ -184,10 +143,9 @@
 	 *
 	 * Returns the result set as an array
 	 *
-	 * @access	private
 	 * @return	array
 	 */
-	function _fetch_assoc()
+	protected function _fetch_assoc()
 	{
 		return cubrid_fetch_assoc($this->result_id);
 	}
@@ -199,16 +157,14 @@
 	 *
 	 * Returns the result set as an object
 	 *
-	 * @access	private
 	 * @return	object
 	 */
-	function _fetch_object()
+	protected function _fetch_object()
 	{
 		return cubrid_fetch_object($this->result_id);
 	}
 
 }
 
-
 /* End of file cubrid_result.php */
-/* Location: ./system/database/drivers/cubrid/cubrid_result.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/cubrid/cubrid_result.php */
diff --git a/system/database/drivers/cubrid/cubrid_utility.php b/system/database/drivers/cubrid/cubrid_utility.php
index 750c0d8..9819abd 100644
--- a/system/database/drivers/cubrid/cubrid_utility.php
+++ b/system/database/drivers/cubrid/cubrid_utility.php
@@ -1,13 +1,13 @@
-<?php  if ( ! defined('BASEPATH')) exit('No direct script access allowed');
+<?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
 /**
  * CodeIgniter
  *
  * An open source application development framework for PHP 5.1.6 or newer
  *
  * NOTICE OF LICENSE
- * 
+ *
  * Licensed under the Open Software License version 3.0
- * 
+ *
  * This source file is subject to the Open Software License (OSL 3.0) that is
  * bundled with this package in the files license.txt / license.rst.  It is
  * also available through the world wide web at this URL:
@@ -21,12 +21,10 @@
  * @copyright	Copyright (c) 2008 - 2012, EllisLab, Inc. (http://ellislab.com/)
  * @license		http://opensource.org/licenses/OSL-3.0 Open Software License (OSL 3.0)
  * @link		http://codeigniter.com
- * @since		Version 1.0
+ * @since		Version 2.1
  * @filesource
  */
 
-// ------------------------------------------------------------------------
-
 /**
  * CUBRID Utility Class
  *
@@ -39,24 +37,11 @@
 	/**
 	 * List databases
 	 *
-	 * @access	private
 	 * @return	array
 	 */
-	function _list_databases()
+	public function list_databases()
 	{
-		// CUBRID does not allow to see the list of all databases on the
-		// server. It is the way its architecture is designed. Every
-		// database is independent and isolated.
-		// For this reason we can return only the name of the currect
-		// connected database.
-		if ($this->conn_id)
-		{
-			return "SELECT '" . $this->database . "'";
-		}
-		else
-		{
-			return FALSE;
-		}
+		return $this->data_cache['db_names'] = cubrid_list_dbs($this->db->conn_id);
 	}
 
 	// --------------------------------------------------------------------
@@ -66,12 +51,11 @@
 	 *
 	 * Generates a platform-specific query so that a table can be optimized
 	 *
-	 * @access	private
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	bool
 	 * @link 	http://www.cubrid.org/manual/840/en/Optimize%20Database
 	 */
-	function _optimize_table($table)
+	public function _optimize_table($table)
 	{
 		// No SQL based support in CUBRID as of version 8.4.0. Database or
 		// table optimization can be performed using CUBRID Manager
@@ -86,12 +70,11 @@
 	 *
 	 * Generates a platform-specific query so that a table can be repaired
 	 *
-	 * @access	private
 	 * @param	string	the table name
-	 * @return	object
+	 * @return	bool
 	 * @link 	http://www.cubrid.org/manual/840/en/Checking%20Database%20Consistency
 	 */
-	function _repair_table($table)
+	public function _repair_table($table)
 	{
 		// Not supported in CUBRID as of version 8.4.0. Database or
 		// table consistency can be checked using CUBRID Manager
@@ -103,11 +86,10 @@
 	/**
 	 * CUBRID Export
 	 *
-	 * @access	private
 	 * @param	array	Preferences
 	 * @return	mixed
 	 */
-	function _backup($params = array())
+	public function _backup($params = array())
 	{
 		// No SQL based support in CUBRID as of version 8.4.0. Database or
 		// table backup can be performed using CUBRID Manager
@@ -117,4 +99,4 @@
 }
 
 /* End of file cubrid_utility.php */
-/* Location: ./system/database/drivers/cubrid/cubrid_utility.php */
\ No newline at end of file
+/* Location: ./system/database/drivers/cubrid/cubrid_utility.php */
diff --git a/user_guide_src/source/changelog.rst b/user_guide_src/source/changelog.rst
index ecf6afc..090681e 100644
--- a/user_guide_src/source/changelog.rst
+++ b/user_guide_src/source/changelog.rst
@@ -55,6 +55,9 @@
    -  Added dsn if the group connections in the config use PDO or any driver which need DSN.
    -  Improved PDO database support.
    -  An optional database name parameter was added db_select().
+   -  Added DSN string support for CUBRID.
+   -  Added persistent connections support for CUBRID.
+   -  CUBRID driver's utility class now overrides list_databases() in order to use cubrid_list_dbs().
 
 -  Libraries