diff --git a/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionColumnsMapping.java b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionColumnsMapping.java
new file mode 100644
index 0000000..4543067
--- /dev/null
+++ b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionColumnsMapping.java
@@ -0,0 +1,53 @@
+package org.gcube.portlets.user.td.gwtservice.shared.tr.union;
+
+import java.io.Serializable;
+
+import org.gcube.portlets.user.td.gwtservice.shared.tr.ColumnData;
+
+/**
+ * 
+ * @author "Giancarlo Panichi"
+ * email: <a href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a> 
+ *
+ */
+public class UnionColumnsMapping  implements Serializable {
+	
+	private static final long serialVersionUID = -8971216501310276805L;
+	
+	protected ColumnData firstColumn;
+	protected ColumnData secondColumn;
+	
+	public UnionColumnsMapping(){
+		
+	}
+	
+	public UnionColumnsMapping(ColumnData firstColumn,ColumnData secondColumn){
+		this.firstColumn=firstColumn;
+		this.secondColumn=secondColumn;
+	}
+
+	public ColumnData getFirstColumn() {
+		return firstColumn;
+	}
+
+	public void setFirstColumn(ColumnData firstColumn) {
+		this.firstColumn = firstColumn;
+	}
+
+	public ColumnData getSecondColumn() {
+		return secondColumn;
+	}
+
+	public void setSecondColumn(ColumnData secondColumn) {
+		this.secondColumn = secondColumn;
+	}
+
+	@Override
+	public String toString() {
+		return "UnionColumnsMapping [firstColumn=" + firstColumn
+				+ ", secondColumn=" + secondColumn + "]";
+	}
+	
+	
+	
+}
diff --git a/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionMonitor.java b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionMonitor.java
new file mode 100644
index 0000000..5365b5a
--- /dev/null
+++ b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionMonitor.java
@@ -0,0 +1,21 @@
+/**
+ * 
+ */
+package org.gcube.portlets.user.td.gwtservice.shared.tr.union;
+
+import java.io.Serializable;
+
+import org.gcube.portlets.user.td.gwtservice.shared.OperationMonitor;
+
+/**
+ * 
+ * @author "Giancarlo Panichi" 
+ * <a href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a> 
+ *
+ */
+public class UnionMonitor extends OperationMonitor implements Serializable {
+
+	
+	private static final long serialVersionUID = -7694151843138161474L;
+			
+}
diff --git a/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionSession.java b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionSession.java
new file mode 100644
index 0000000..cd9d113
--- /dev/null
+++ b/src/main/java/org/gcube/portlets/user/td/gwtservice/shared/tr/union/UnionSession.java
@@ -0,0 +1,66 @@
+package org.gcube.portlets.user.td.gwtservice.shared.tr.union;
+
+import java.io.Serializable;
+import java.util.ArrayList;
+
+import org.gcube.portlets.user.td.gwtservice.shared.tr.TabResource;
+import org.gcube.portlets.user.td.widgetcommonevent.shared.TRId;
+
+/**
+ * 
+ * @author "Giancarlo Panichi" <a
+ *         href="mailto:g.panichi@isti.cnr.it">g.panichi@isti.cnr.it</a>
+ * 
+ */
+public class UnionSession implements Serializable {
+
+	private static final long serialVersionUID = -1896235499708614266L;
+
+	protected TRId trId;
+	protected TabResource unionTabularResource;
+	protected ArrayList<UnionColumnsMapping> columnsMatch;
+
+	public UnionSession() {
+
+	}
+
+	public UnionSession(TRId trId, TabResource unionTabularResource,
+			ArrayList<UnionColumnsMapping> columnsMatch) {
+		this.trId = trId;
+		this.unionTabularResource=unionTabularResource;
+		this.columnsMatch=columnsMatch;
+		
+	}
+
+	public TRId getTrId() {
+		return trId;
+	}
+
+	public void setTrId(TRId trId) {
+		this.trId = trId;
+	}
+
+	public TabResource getUnionTabularResource() {
+		return unionTabularResource;
+	}
+
+	public void setUnionTabularResource(TabResource unionTabularResource) {
+		this.unionTabularResource = unionTabularResource;
+	}
+
+	public ArrayList<UnionColumnsMapping> getColumnsMatch() {
+		return columnsMatch;
+	}
+
+	public void setColumnsMatch(ArrayList<UnionColumnsMapping> columnsMatch) {
+		this.columnsMatch = columnsMatch;
+	}
+
+	@Override
+	public String toString() {
+		return "UnionSession [trId=" + trId + ", unionTabularResource="
+				+ unionTabularResource + ", columnsMatch=" + columnsMatch + "]";
+	}
+
+	
+}