Time consuming for drop column

I have to drop column from table which have about 2,000,000 rows.

Which is the less time consuming ?

    the one is just 'alter table <table> drop column ...'     the other is 'update <table> set <column to drop> = NULL ,... '

        and after 'alter table <table> drop column ...'

Thanks in advance. Received on Thu Aug 09 2001 - 21:48:41 CDT