RE: Large databases

After dragging Kevin Loney's name into discussion, I thought I should give the reference. So I scrounged around and found the book. It's the Oracle DBA Handbook for Oracle 7.3; page 246 in Chapter 8 "Database Tuning".

The author first quotes another author to start the sub-topic of "Effective Table Design". The quote is:
"No major application will run in Third Normal Form" -- George Koch from
Oracle 7, The Complete Reference.

Kevin (or whoever wrote this section) goes on to write:

No matter how well designed your database is, poor table design will lead to poor performance. Not only that, but overly rigid adherence to relational table design will lead to poor performance. That is due to the fact that while fully relational table designs (said to be in the Third Normal Form) are logically desirable, they are physically undesirable.

The problem with such designs is that although they accurately reflect the ways in which an application's data is related to other data, they do not reflect the normal access paths that users will employ to access that data.

... the discussion goes on until we get to ...

User-centered table design, rather than theory-centered table design, will yield systems that better meet the users' requirements.

And now a few words from our sponsor:

As I thought about the application I mentioned in a previous post, I recalled that there were joins of 13 tables. As one might suspect, these were a little on the slow side. And all the king's horses and all the king's men couldn't speed them up. And don't think they didn't try.

"Uh, can you do some performance tuning on this query?"

"HUH?!?! You're joining 13 tables here!"

I recall somebody deriding a non-fully normalized database as being a maintenance problem. Well ... How would like to maintain the SQL for the baby (Rosemary's, of course) of which I speak?

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Author: Stephen Lee
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