SQL Performance question

If memory serves me right, this:
... WHERE EXISTS ( ....
would normally perform better than
... WHERE <column> IN ( ...

I have an example of the opposite, which is confirmed by EXPLAIN PLAN (there is a table scan in the EXISTS version). So, I wonder:
- memory serves me wrong

• this used to be true, but not anymore
• this is normally true, it is probably just wrong for this exact statement
• other?

Oracle 8.0.5.

TIA,
D A Received on Thu Oct 05 2000 - 09:13:54 CDT