problem with Search module in drupal

I've problem with the search modu开发者_如何学Gole in drupal. When I do a seach, it return 0 results even-though there are patterns matching. I ran the cron manually and flushed the cache. Now, the search module works fine.

I wanna know whether I should do this procedure regularly for the search module to work?

thanks.

clearing cache is not need, running cron is main
read here how to do: http://drupal.org/cron