application.ini
    [production]
    resources.view[] =
    resources.db.adapter = PDO_MYSQL
    resources.db.params.host = localhost
    resources.db.params.username = xxxx
    resources.db.params.password = xxxx
    resources.db.params.dbname = mydb
    resources.layout.layoutPath = APPLICATION_PATH "/layouts/scripts/"
    ; following line added
    resources.db.params.profiler.enabled = "true"
    resources.db.params.profiler.class = "Zend_Db_Profiler_Firebug"

    <?php
    class LoginController extends Zend_Controller_Action
    {
      public function indexAction()
      {
        // Database connection
        $config = new Zend_Config_Ini(APPLICATION_PATH . '/configs/application.ini', 'production');
        // we already told in our application ini else
        //$profiler = new Zend_Db_Profiler_Firebug('All DB Queries');
        //$profiler->setEnabled(true);
        $db = Zend_Db::factory($config->resources->db);
        $this->db = $db;
        // this query will be showing in profiler
        $db->query("select *from clients");
        /**
          Zend_Db_Profiler_Firebug (2 @ 0.000180 sec)
          Time	Event	Parameters
          ====        =====   ===========
          0.00061	connect	NULL
          0.00057	select *from clients	NULL

        */
      }
    }