CDbCriteria getting loads of data need only few selected

My controller code

	 $criteria = new CDbCriteria();


	  $criteria->compare('status', $_POST['Details']['status'], false, 'AND');

     

          $criteria->compare('gender',  $_POST['Details']['gender'], false, 'AND');

     

        


$dataProvider=new CActiveDataProvider('Details', array(

    'criteria'=>$criteria,

    'pagination'=>array(

        'pageSize'=>20,

    ),

));

Now I get my results properly but the thing is even get extra columns that I don’t need and all the relations that are there in Details model are executed, this is making my results show slow,

I just want certain columns to be selected from Details, and certain relations to be executed and get their columns.

How will I achieve this I am trying to use

$criteria->select('column names seperated with commas');

try this -

$criteria->select = array('status', 'gender', 'age');

$criteria->select = "column1,column2,column3";

This gives me errors

What kind of errors? Ambiguous columns?

The given syntax is right,can you tell me the errors.