Question

I have a table with 3 columns cost, from_date and to_date. I have to select all the rows which do not have the dates from beginning of the month to the end of the month. That is, select rows which do not have the from_date as ‘1-NOV-2011′ and to_date as ’30-NOV-2011’. I’ve written 2 queries.

SELECT * FROM TABLE1 WHERE FROM_DATE <> '1-NOV-2011' OR TO_DATE <> '30-NOV-2011';

and

SELECT * FROM TABLE1 MINUS SELECT * FROM TABLE1 WHERE FROM_DATE = '1-NOV-2011' AND TO_DATE = '30-NOV-2011';

Which one will give a better performance?

Answer 1

1st one is better, since that involves only a single scan also that does not contains any ‘in’s or ‘not in’s. go for 1st first one…