NOT USING A NOT IN SQL

What are some equivalent ways of SQL coding to avoid a 'not' in the following sql clause. I'm vaguely familiar with 'exists' and 'minus'. The rule I've heard is never use a not - it takes much longer to return a result. Does anyone have experience with not using a 'not'?

select c1 from table where c1 not in(select c2 from another_table);

(c1 and c2 would have similar values)

Thank you in advance for any advice,

D. Tharpe Received on Mon Aug 17 1998 - 10:01:50 CDT