diff --git a/src/main/java/org/gcube/portlets/user/td/gwtservice/server/SessionConstants.java b/src/main/java/org/gcube/portlets/user/td/gwtservice/server/SessionConstants.java
index 4e1cb65..5efc2e1 100644
--- a/src/main/java/org/gcube/portlets/user/td/gwtservice/server/SessionConstants.java
+++ b/src/main/java/org/gcube/portlets/user/td/gwtservice/server/SessionConstants.java
@@ -127,4 +127,9 @@ public class SessionConstants {
 	
 	public static final String RULES_ON_TABLE_DETACH_SESSION = "RULES_ON_TABLE_DETACH_SESSION";
 
+	public static final String COLUMN_FILTER_SESSION = "COLUMN_FILTER_SESSION";
+	
+	public static final String COLUMN_FILTER_SESSION_TASK = "COLUMN_FILTER_SESSION_TASK";
+
+	
 }