Re: Unindexed FK and DW

From: <gromanescu_at_gmail.com>
Date: 7 Nov 2006 10:39:14 -0800
Message-ID: <1162924754.105550.89990@k70g2000cwa.googlegroups.com>

klabu wrote:
> Is Unindexed FK a common thing in Data Warehouse ?
>

Common or not ... is hardly the question, irrelevant really on speculating on what many might or might not do out there.

The question is whether is a good idea not to have indexes on the FKs of the fact?

Well, be ready to take some performance hits on certain classes of queries ... be ready to preclude some of the optimization techniques the Oracle server has available.

Interestingly, bitmap index are appropriate exactly for this type of scenario ... more or less, forget about this feature too.

What now ... full table scan of the fact table every single time? And if I add composite indexes ... how many of them? ... and what is the order of the columns in each of the composites? Received on Tue Nov 07 2006 - 12:39:14 CST