diff --git a/web/pgadmin/browser/server_groups/servers/static/js/privilege.js b/web/pgadmin/browser/server_groups/servers/static/js/privilege.js
index 2f6f0524b..7d2ccc4c0 100644
--- a/web/pgadmin/browser/server_groups/servers/static/js/privilege.js
+++ b/web/pgadmin/browser/server_groups/servers/static/js/privilege.js
@@ -59,6 +59,7 @@
       grantor: undefined,
       privileges: undefined
     },
+    keys: ['grantee', 'grantor'],
     /*
      * Each of the database object needs to extend this model, which should
      * provide the type of privileges (it supports).
@@ -67,7 +68,7 @@
 
     schema: [{
       id: 'grantee', label:'Grantee', type:'text', group: null, cell: 'string',
-      disabled: true, cellHeaderClasses: 'width_percent_40'
+      disabled: false, cellHeaderClasses: 'width_percent_40'
     }, {
       id: 'privileges', label:'Privileges',
       type: 'collection', model: PrivilegeModel, group: null,
@@ -93,7 +94,8 @@
         privileges = new (pgNode.Collection)(
             models, {
               model: PrivilegeModel,
-              handler: this.handler || this,
+              top: this.top || this,
+              handler: this,
               silent: true,
               parse: false
             });
diff --git a/web/pgadmin/browser/server_groups/servers/static/js/variable.js b/web/pgadmin/browser/server_groups/servers/static/js/variable.js
index 660b65d9f..bb6895163 100644
--- a/web/pgadmin/browser/server_groups/servers/static/js/variable.js
+++ b/web/pgadmin/browser/server_groups/servers/static/js/variable.js
@@ -38,10 +38,11 @@
   var VariableModel = pgNode.VariableModel = pgNode.Model.extend({
     defaults: {
       name: undefined,
-      value: undefined,
+      value: '',
       role: undefined,
       database: undefined,
     },
+    keys: ['name', 'role', 'database'],
     schema: [
       {id: 'name', label:'Name', type:'text', editable: false, cellHeaderClasses: 'width_percent_30'},
       {
@@ -57,7 +58,7 @@
       // Remove not defined values from model values.
       // i.e.
       // role, database
-      if (_.isUndefined(d.database)) {
+      if (_.isUndefined(d.database) || _.isNull(d.database)) {
         delete d.database;
       }
 
@@ -66,6 +67,20 @@
       }
 
       return d;
+    },
+    validate: function() {
+      if (_.isUndefined(this.get('value')) ||
+          String(this.get('value')).replace(/^\s+|\s+$/g, '') == '') {
+        var msg = 'Please enter some value!';
+
+        this.errorModel.set('value', msg);
+
+        return msg;
+      } else {
+        this.errorModel.unset('value');
+      }
+
+      return null;
     }
   });
 
@@ -306,7 +321,10 @@
           url = this.field.get('url'),
           m = self.model;
 
-      if (this.field.get('version_compitible') && url && !m.isNew()) {
+      if (!this.field.get('version_compitible'))
+        return;
+
+      if (url && !m.isNew()) {
         var node = self.field.get('node'),
             node_data = self.field.get('node_data'),
             node_info = self.field.get('node_info'),
@@ -314,9 +332,14 @@
               node, [
                 null, url, node_data, true, node_info
               ]),
-            data;
+            data,
+            isTracking = self.collection.trackChanges;
+
+        if (isTracking) {
+          self.collection.stopSession();
+        }
+        m.trigger('pgadmin-view:fetching', m, self.field);
 
-        m.trigger('pgadmin:view:fetching', m, self.field);
         $.ajax({
           async: false,
           url: full_url,
@@ -324,19 +347,20 @@
             data = res.data;
           },
           error: function() {
-            m.trigger('pgadmin:view:fetch:error', m, self.field);
+            m.trigger('pgadmin-view:fetch:error', m, self.field);
           }
         });
-        m.trigger('pgadmin:view:fetched', m, self.field);
+        m.trigger('pgadmin-view:fetched', m, self.field);
 
         if (data && _.isArray(data)) {
           self.collection.reset(data, {silent: true});
-          /*
-           * Make sure - new data will be taken care by the session management
-           */
+        }
+        /*
+         * Make sure - new data will be taken care by the session management
+         */
+        if (isTracking) {
           self.collection.startNewSession();
         }
-      } else {
       }
     },
 
@@ -417,11 +441,8 @@
     },
 
     events: _.extend(
-                {},
-                Backform.UniqueColCollectionControl.prototype.events,
-                {
-                  'click button.add': 'addVariable'
-                }
+                {}, Backform.UniqueColCollectionControl.prototype.events,
+                {'click button.add': 'addVariable'}
                 ),
 
     showGridControl: function(data) {
@@ -481,8 +502,10 @@
 
       var self = this,
           m = new (self.field.get('model'))(
-                self.headerData.toJSON(), {silent: true}
-                ),
+                self.headerData.toJSON(), {
+                  silent: true, top: self.collection.top,
+                  handler: self.collection
+                }),
           coll = self.model.get(self.field.get('name'));
 
       coll.add(m);
diff --git a/web/pgadmin/browser/static/js/node.ui.js b/web/pgadmin/browser/static/js/node.ui.js
index 7642a47da..722cab320 100644
--- a/web/pgadmin/browser/static/js/node.ui.js
+++ b/web/pgadmin/browser/static/js/node.ui.js
@@ -69,7 +69,7 @@ function($, _, pgAdmin, Backbone, Backform, Alertify, Node) {
        */
       var self = this,
           url = self.field.get('url') || self.defaults.url,
-          m = self.model.handler || self.model;
+          m = self.model.top || self.model;
 
       // Hmm - we found the url option.
       // That means - we needs to fetch the options from that node.
diff --git a/web/pgadmin/static/js/backform.pgadmin.js b/web/pgadmin/static/js/backform.pgadmin.js
index 42aaa5574..fb8010e5c 100644
--- a/web/pgadmin/static/js/backform.pgadmin.js
+++ b/web/pgadmin/static/js/backform.pgadmin.js
@@ -149,7 +149,7 @@
           attrArr = d.split('.');
           name = attrArr.shift();
 
-          self.stopListening(that.model, "change:" + name, self.render);
+          self.stopListening(self.model, "change:" + name, self.render);
         });
       }
 
@@ -451,11 +451,11 @@
           'hidden.bs.tab', function() {
             self.hidden_tab = $(this).data('tabIndex');
             }).on('shown.bs.tab', function() {
-              var that = this;
-              self.shown_tab = $(that).data('tabIndex');
+              var self = this;
+              self.shown_tab = $(self).data('tabIndex');
               m.trigger('pg-property-tab-changed', {
                 'model': m, 'shown': self.shown_tab, 'hidden': self.hidden_tab,
-                'tab': that
+                'tab': self
               });
             });
       });
@@ -650,7 +650,8 @@
               {
                 model: self.field.get('model'),
                 silent: true,
-                handler: self.model.handler || self.model
+                handler: self.model.handler || self.model,
+                attrName: self.field.get('name')
               });
           self.model.set(self.field.get('name'), collection, {silent: true});
         }
@@ -664,8 +665,8 @@
       var self = this;
 
       if (this.field.get('version_compitible')) {
-        self.stopListening(collection, "add", self.collectionChanged);
-        self.stopListening(collection, "change", self.collectionChanged);
+        self.stopListening(self.collection, "add", self.collectionChanged);
+        self.stopListening(self.collection, "change", self.collectionChanged);
       }
 
       Backform.Control.prototype.remove.apply(this, arguments);
@@ -1084,13 +1085,13 @@
       this.sqlTab = sqlTab;
       return this;
     },
-    onTabChange: function() {
+    onTabChange: function(obj) {
 
       // Fetch the information only if the SQL tab is visible at the moment.
-      if (this.dialog && this.dialog.shown_tab == this.tabIndex) {
+      if (this.dialog && obj.shown == this.tabIndex) {
 
         // We will send request to sever only if something is changed in model
-        if(_.size(this.model.sessAttrs)) {
+        if(this.model.sessChanged()) {
 
           var self = this,
             node = self.field.get('schema_node'),