diff --git a/src/helma/objectmodel/db/NodeManager.java b/src/helma/objectmodel/db/NodeManager.java
index f2a8d880..4c3e1c0c 100644
--- a/src/helma/objectmodel/db/NodeManager.java
+++ b/src/helma/objectmodel/db/NodeManager.java
@@ -443,6 +443,7 @@ public final class NodeManager {
 	// tx.timer.beginEvent ("updateNode "+node);
 
 	DbMapping dbm = node.getDbMapping ();
+	boolean markMappingAsUpdated = false;
 
 	if (dbm == null || !dbm.isRelational ()) {
 	    db.saveNode (txn, node.getID (), node);
@@ -503,6 +504,8 @@ public final class NodeManager {
 	                            break;
 	                    }
 	                    p.dirty = false;
+	                    if (!rel.isPrivate())
+	                        markMappingAsUpdated = true;
 	                }
 
 	            } else if (rel != null && rel.getDbField() != null) {
@@ -522,7 +525,8 @@ public final class NodeManager {
 	            tds.close ();
 	        } catch (Exception ignore) {}
 	    }
-	    dbm.notifyDataChange ();
+	    if (markMappingAsUpdated)
+	        dbm.notifyDataChange ();
 	}
 	// update may cause changes in the node's parent subnode array
 	if (node.isAnonymous()) {
diff --git a/src/helma/objectmodel/db/Relation.java b/src/helma/objectmodel/db/Relation.java
index 57c514fa..d562e74c 100644
--- a/src/helma/objectmodel/db/Relation.java
+++ b/src/helma/objectmodel/db/Relation.java
@@ -53,6 +53,7 @@ public final class Relation {
     boolean aggressiveLoading;
     boolean aggressiveCaching;
     boolean subnodesAreProperties;
+    boolean isPrivate;
     String accessor; // db column used to access objects through this relation
     String order;
     String groupbyorder;
@@ -132,13 +133,15 @@ public final class Relation {
 	        columnName = desc;
 	        reftype = PRIMITIVE;
 	    }
-	    String rdonly = props.getProperty (desc+".readonly");
-	    if (rdonly != null && "true".equalsIgnoreCase (rdonly)) {
-	        readonly = true;
-	    } else {
-	        readonly = false;
-	    }
 	}
+	String rdonly = props.getProperty (desc+".readonly");
+	if (rdonly != null && "true".equalsIgnoreCase (rdonly)) {
+	    readonly = true;
+	} else {
+	    readonly = false;
+	}
+	isPrivate = "true".equalsIgnoreCase (props.getProperty (desc+".private"));
+
 	// the following options only apply to object and collection relations
 	if (reftype != PRIMITIVE && reftype != INVALID) {
 
@@ -408,6 +411,15 @@ public final class Relation {
 	return readonly;
     }
 
+    /**
+     *  Tell wether the property described by this relation is to be handled as private, i.e.
+     *  a change on it should not result in any changed object/collection relations.
+     */
+    public boolean isPrivate () {
+	return isPrivate;
+    }
+
+
     /**
      * Check if the child node fullfills the constraints defined by this relation.
      */