diff --git a/modules/document/document.class.php b/modules/document/document.class.php
index d7cc50134..032a9ec06 100644
--- a/modules/document/document.class.php
+++ b/modules/document/document.class.php
@@ -87,9 +87,6 @@ class Document extends ModuleObject
 		if(!$oDB->isIndexExists("document_extra_vars", "unique_extra_vars")) return true;
 		if($oDB->isIndexExists("document_extra_vars", "unique_module_vars")) return true;
 
-		// 2011. 03. 30 Cubrid index Check the index in the document_extra_vars table
-		if(!$oDB->isIndexExists("document_extra_vars", "idx_document_list_order")) return true;
-
 		// 2011. 10. 25 status index check
 		if(!$oDB->isIndexExists("documents", "idx_module_status")) return true;
 
@@ -117,6 +114,9 @@ class Document extends ModuleObject
 		if(!$oDB->isColumnExists('document_extra_keys', 'var_sort')) return true;
 		if(!$oDB->isColumnExists('document_extra_vars', 'sort_value') || !$oDB->isIndexExists('document_extra_vars', 'idx_sort_value')) return true;
 
+		// Delete unnecessary index
+		if($oDB->isIndexExists('document_extra_vars', 'idx_document_list_order')) return true;
+
 		return false;
 	}
 
@@ -182,12 +182,7 @@ class Document extends ModuleObject
 			$oDB->dropIndex("document_extra_vars", "unique_module_vars", true);
 		}
 
-		// 2011. 03. 30 Cubrid index Check the index in the document_extra_vars table
-		if(!$oDB->isIndexExists("document_extra_vars", "idx_document_list_order"))
-		{
-			$oDB->addIndex("document_extra_vars", "idx_document_list_order", array("document_srl","module_srl","var_idx"), false);
-		}
-
+		// 2011. 10. 25 status index check
 		if(!$oDB->isIndexExists("documents", "idx_module_status"))
 		{
 			$oDB->addIndex("documents", "idx_module_status", array("module_srl","status"));
@@ -266,7 +261,13 @@ class Document extends ModuleObject
 				}
 			}
 			$oDB->commit();
-			$oDB->addIndex('document_extra_vars', 'idx_sort_value', array('sort_value'));
+			$oDB->addIndex('document_extra_vars', 'idx_sort_value', array('module_srl', 'sort_value'));
+		}
+
+		// Delete unnecessary index
+		if($oDB->isIndexExists('document_extra_vars', 'idx_document_list_order'))
+		{
+			$oDB->dropIndex('document_extra_vars', 'idx_document_list_order');
 		}
 	}
 
diff --git a/modules/document/queries/updateDocumentExtraVarSortValue.xml b/modules/document/queries/updateDocumentExtraVarSortValue.xml
index f7b3e59ca..771aa80b7 100644
--- a/modules/document/queries/updateDocumentExtraVarSortValue.xml
+++ b/modules/document/queries/updateDocumentExtraVarSortValue.xml
@@ -3,7 +3,7 @@
 		<table name="document_extra_vars" />
 	</tables>
 	<columns>
-		<column name="sort_value" default="CAST(value AS UNSIGNED)" />
+		<column name="sort_value" default="CAST(value AS SIGNED)" />
 	</columns>
 	<conditions>
 		<condition operation="equal" column="module_srl" var="module_srl" filter="number" notnull="notnull" />
diff --git a/modules/document/schemas/document_extra_vars.xml b/modules/document/schemas/document_extra_vars.xml
index bb24e1044..dc3455a3d 100644
--- a/modules/document/schemas/document_extra_vars.xml
+++ b/modules/document/schemas/document_extra_vars.xml
@@ -1,9 +1,10 @@
 <table name="document_extra_vars">
-    <column name="module_srl" type="number" size="11" notnull="notnull" unique="unique_extra_vars" />
-    <column name="document_srl" type="number" size="11" notnull="notnull" unique="unique_extra_vars" />
-    <column name="var_idx" type="number" size="11" notnull="notnull" unique="unique_extra_vars" />
-    <column name="lang_code" type="varchar" size="10" notnull="notnull" unique="unique_extra_vars" />
-    <column name="value" type="bigtext" />
-	<column name="sort_value" type="bigint" index="idx_sort_value" />
-    <column name="eid" type="varchar" size="40" />
+	<column name="module_srl" type="number" size="11" notnull="notnull" unique="unique_extra_vars" />
+	<column name="document_srl" type="number" size="11" notnull="notnull" unique="unique_extra_vars" />
+	<column name="var_idx" type="number" size="11" notnull="notnull" unique="unique_extra_vars" />
+	<column name="lang_code" type="varchar" size="10" notnull="notnull" unique="unique_extra_vars" />
+	<column name="value" type="bigtext" />
+	<column name="sort_value" type="bigint" />
+	<column name="eid" type="varchar" size="40" />
+	<index name="idx_sort_value" columns="module_srl,sort_value" />
 </table>