query enhancement

I am attempting to enhance a query so as to avoid a full table scan. The query, as it now stands, tests for the presence of 'null' in one column; the return of 1 or greater rows will satisfy my test, therefore I'd like the query to stop after finding the first occurrence of null. present query is as follows:

  select count(*) from tableX where columnX = null.

Any suggestions would be greatly appreciated. Received on Fri Jun 15 2007 - 12:22:45 CDT