Where col in (num, num) vs where col in (select # from tab)

I have a rather nasty query.. If I do a:

select columns from tables where col_value in (num1, num2, num3)

it takes several minutes. If I do a:

select columns from tables where col_value in (select num from temptable)

it runs much faster.

Any ideas why a where col in (list of values) is so much slower than where col in (select list of values from a table) ?

thx.. Allen Received on Thu Jun 13 2002 - 14:26:39 CDT