diff --git a/classes/db/DB.class.php b/classes/db/DB.class.php
index 09ca3e2eb..f312ff97e 100644
--- a/classes/db/DB.class.php
+++ b/classes/db/DB.class.php
@@ -26,21 +26,6 @@ class DB
 		'mysql' => 1,
 	);
 
-	/**
-	 * operations for condition
-	 * @var array
-	 */
-	protected static $cond_operation = array(
-		'equal' => '=',
-		'more' => '>=',
-		'excess' => '>',
-		'less' => '<=',
-		'below' => '<',
-		'notequal' => '<>',
-		'notnull' => 'is not null',
-		'null' => 'is null',
-	);
-
 	/**
 	 * master database connection string
 	 * @var array
@@ -705,6 +690,7 @@ class DB
 
 		$tableObjects = $query->getTables();
 		$index_hint_list = '';
+		/*
 		foreach($tableObjects as $tableObject)
 		{
 			if(is_a($tableObject, 'CubridTableWithHint'))
@@ -717,6 +703,7 @@ class DB
 		{
 			$index_hint_list = 'USING INDEX ' . $index_hint_list;
 		}
+		*/
 
 		$groupBy = $query->getGroupByString();
 		if($groupBy != '')
diff --git a/classes/db/queryparts/table/CubridTableWithHint.class.php b/classes/db/queryparts/table/CubridTableWithHint.class.php
deleted file mode 100644
index 9f614a816..000000000
--- a/classes/db/queryparts/table/CubridTableWithHint.class.php
+++ /dev/null
@@ -1,71 +0,0 @@
-<?php
-/* Copyright (C) NAVER <http://www.navercorp.com> */
-
-/**
- * @author NAVER (developers@xpressengine.com)
- * @package /classes/db/queryparts/table
- * @version 0.1
- */
-class CubridTableWithHint extends Table
-{
-
-	/**
-	 * table name
-	 * @var string
-	 */
-	var $name;
-
-	/**
-	 * table alias
-	 * @var string
-	 */
-	var $alias;
-
-	/**
-	 * index hint list
-	 * @var array
-	 */
-	var $index_hints_list;
-
-	/**
-	 * constructor
-	 * @param string $name
-	 * @param string $alias
-	 * @param array $index_hints_list
-	 * @return void
-	 */
-	function __construct($name, $alias = NULL, $index_hints_list)
-	{
-		parent::__construct($name, $alias);
-		$this->index_hints_list = $index_hints_list;
-	}
-
-	/**
-	 * Return index hint string
-	 * @return string
-	 */
-	function getIndexHintString()
-	{
-		$result = '';
-
-		// Retrieve table prefix, to add it to index name
-		$prefix = config('db.master.prefix');
-
-		foreach($this->index_hints_list as $index_hint)
-		{
-			$index_hint_type = $index_hint->getIndexHintType();
-			if($index_hint_type !== 'IGNORE')
-			{
-				$result .= $this->alias . '.'
-						. '"' . $prefix . substr($index_hint->getIndexName(), 1)
-						. ($index_hint_type == 'FORCE' ? '(+)' : '')
-						. ', ';
-			}
-		}
-		$result = substr($result, 0, -2);
-		return $result;
-	}
-
-}
-/* End of file CubridTableWithHint.class.php */
-/* Location: ./classes/db/queryparts/table/CubridTableWithHint.class.php */
diff --git a/classes/db/queryparts/table/MssqlTableWithHint.class.php b/classes/db/queryparts/table/MssqlTableWithHint.class.php
deleted file mode 100644
index edc49accc..000000000
--- a/classes/db/queryparts/table/MssqlTableWithHint.class.php
+++ /dev/null
@@ -1,66 +0,0 @@
-<?php
-/* Copyright (C) NAVER <http://www.navercorp.com> */
-
-/**
- * @author NAVER (developers@xpressengine.com)
- * @package /classes/db/queryparts/table
- * @version 0.1
- */
-class MssqlTableWithHint extends Table
-{
-
-	/**
-	 * table name
-	 * @var string
-	 */
-	var $name;
-
-	/**
-	 * table alias
-	 * @var string
-	 */
-	var $alias;
-
-	/**
-	 * index hint type, ex) IGNORE, FORCE, USE...
-	 * @var array
-	 */
-	var $index_hints_list;
-
-	/**
-	 * constructor
-	 * @param string $name
-	 * @param string $alias
-	 * @param string $index_hints_list
-	 * @return void
-	 */
-	function __construct($name, $alias = NULL, $index_hints_list)
-	{
-		parent::__construct($name, $alias);
-		$this->index_hints_list = $index_hints_list;
-	}
-
-	function toString()
-	{
-		$result = parent::toString();
-
-		$index_hint_string = '';
-		$indexTypeList = array('USE' => 1, 'FORCE' => 1);
-		foreach($this->index_hints_list as $index_hint)
-		{
-			$index_hint_type = $index_hint->getIndexHintType();
-			if(isset($indexTypeList[$index_hint_type]))
-			{
-				$index_hint_string .= 'INDEX(' . $index_hint->getIndexName() . '), ';
-			}
-		}
-		if($index_hint_string != '')
-		{
-			$result .= ' WITH(' . substr($index_hint_string, 0, -2) . ') ';
-		}
-		return $result;
-	}
-
-}
-/* End of file MssqlTableWithHint.class.php */
-/* Location: ./classes/db/queryparts/table/MssqlTableWithHint.class.php */
diff --git a/common/autoload.php b/common/autoload.php
index c4312273c..cbcd870ba 100644
--- a/common/autoload.php
+++ b/common/autoload.php
@@ -66,10 +66,8 @@ $GLOBALS['RX_AUTOLOAD_FILE_MAP'] = array_change_key_case(array(
 	'UpdateExpressionWithoutArgument' => 'classes/db/queryparts/expression/UpdateExpressionWithoutArgument.class.php',
 	'Limit' => 'classes/db/queryparts/limit/Limit.class.php',
 	'OrderByColumn' => 'classes/db/queryparts/order/OrderByColumn.class.php',
-	'CubridTableWithHint' => 'classes/db/queryparts/table/CubridTableWithHint.class.php',
 	'IndexHint' => 'classes/db/queryparts/table/IndexHint.class.php',
 	'JoinTable' => 'classes/db/queryparts/table/JoinTable.class.php',
-	'MssqlTableWithHint' => 'classes/db/queryparts/table/MssqlTableWithHint.class.php',
 	'MysqlTableWithHint' => 'classes/db/queryparts/table/MysqlTableWithHint.class.php',
 	'Table' => 'classes/db/queryparts/table/Table.class.php',
 	'DisplayHandler' => 'classes/display/DisplayHandler.class.php',