Hi Virusno1,

Good question! Looks like you are talking about SQL server. It's hard to hit you back with the right answer since question itself is not that clear to me. First of all,  I just want to know if you are using 2000, 2005 or 2008, since lots of new techniques has been added. I don't think its a best idea to run profiler all the time since it will slow down the server.  You can create and schedule a job to run DBCC dbreindex or update statistics and run it when server usage is minimal. You can even used 3rd party tools like quest's spotlight, Foglight etc to monitor and tune database.

However, if you are talking about slowing down of particular query, you might have to do extra sit ups to find out what exactly is slowing down, are there too many joins, have lots of data been changed lately, are  your tables heavily fragmented, have your query using any sproc etc.

Once again, these are not all the possible answers. Do you have problem with the server itself? Does you server has enough memory? Is sql server configured to use available memory?  I don't think sajha will be the best site if you are really looking for answer. Please, try to go to microsoft's website or Sq-server-performance.com etc. where you can meet  with people who had given there lives to these technologies.

I hope this at least helped you a little bit. I wish you all the best.

Thanks