diff --git a/js/search/search_form_criteria.js b/js/search/search_form_criteria.js
index 13fa5ab18..3967a3e9f 100644
--- a/js/search/search_form_criteria.js
+++ b/js/search/search_form_criteria.js
@@ -20,6 +20,7 @@ $(function()
 				'label': '',
 				'allowed_values': null,
 				'is_null_allowed': false,
+				'has_index': false,
 			},
 			// Available operators. They can be extended or restricted by derivated widgets (see this._initOperators() for more informations)
 			'available_operators': {
@@ -61,9 +62,14 @@ $(function()
 			// Init properties (complexe type properties would be static if not initialized with a simple type variable...)
 			this.operators = {};
 
+
+            // Choose the default operator
+            this._initChooseDefaultOperator();
+
 			// Init operators
 			this._initOperators();
 
+
 			// Link search form handler
 			this.handler = this.element.closest('.search_form_handler');
 
@@ -95,7 +101,14 @@ $(function()
 			this._super( key, value );
 		},
 
-
+        _initChooseDefaultOperator: function() {
+            //if the class has an index, in order to maximize the performance, we force the default operator to "equal"
+            if (this.options.field.has_index && typeof this.options.available_operators['='] == 'object')
+            {
+                this.options.operator = '=';
+                this.options.available_operators['='].rank = -1;//we want it to be the first displayed
+            }
+        },
 		// Protected methods
 		// - Init operators by cleaning up available operators and ordering them.
 		//   Note: A null operator or an operator with a rank "false" will be removed.
@@ -104,6 +117,8 @@ $(function()
 			// Reset operators
 			this.operators = {};
 
+
+
 			// Cancel empty/not_empty operators if field can't be null
 			if(this.options.field.is_null_allowed === false)
 			{
diff --git a/js/search/search_form_handler.js b/js/search/search_form_handler.js
index 84884b6d6..98644614f 100644
--- a/js/search/search_form_handler.js
+++ b/js/search/search_form_handler.js
@@ -811,7 +811,8 @@ $(function()
 					label: oFieldDef.label,
 					class: oFieldDef.class,
 					class_alias: oFieldDef.class_alias,
-					code: oFieldDef.code,
+                    code: oFieldDef.code,
+                    has_index: oFieldDef.has_index,
 					target_class: oFieldDef.target_class,
 					widget: oFieldDef.widget,
 					allowed_values: oFieldDef.allowed_values,