Good article David.

But the first thing I thought was: Oh no, not another discussion on DRI...

Sounds a bit defeatist but, as with so many things it's impossible to get everything...

Hi Mike

Here's an explanation on using UNKNOWN with SQL2003: http://msdn2.microsoft.com/en-us/library/ms188074.aspx

To test this I created a table:

CREATE TABLE t1([a] [int] NULL)

GO

INSERT INTO t1 (a) VALUES (NULL)

INSERT INTO t1 (a) VALUES...

Mike, good point about NOT IN not being SARGable in the WHERE clause. However, using "three comparisons in SQL-92" (IF...THEN...ELSE) would certainly not be very effecient for multiple row data...

Ahh, trying to find the great "Unknown", very philosophical Tom.

I think many comments have alluded to the idea that that is the only true purpose of using NULL (other than...

Yeah, ironically, Greenspan was being confusing for all the right reasons, or at least that's how it appears. Just wonder how intelligent he's going to look when the 'merican creditors...

Well no one ever accussed Rumsfeld of being unoriginal, kind of reminds me of another expression I really like: "bullsh*t baffles brains".

Baffling aside, NULL can be a real problem especially...

Yes, well, some of us started feeling a little queasy when the name Donald Rumsfeld popped up on our periphary but managed to relegate it to the suppressed memory partition. Thanks...

I respect your comments and research on using NULLS but can't understand why you just don't use the correct querying method with NULLS.

Your comment: "Because of the inherent issues surrounding NULLs...

The Dynamic Management Views and Functions are great.

I'd like to have an interface listing these functions (multi-selectable) in one window and an option of relevant windows with the active processs (according to...

True, the format might indeed be better and more efficient for those receiving the requests and make no mistake many of us have also tried to implement these sort of processes and...

Idealism vs. Realism, I'd like to see that on "Celebrity Deathmatch"!

In response to Chris's request for information on data integrity: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/createdb/cm_8_des_02_3bsp.asp

Paul is correct, referential integrity can be used to enforce business rules: e.g defining the data flow in business processes. The single column primary key example though, enforces the integrity of the given business...

but why, WHY!!! All I wanted was to script some procs, maybe some udf's, not too much to ask for. Why did this have to happen to me!

Ok, I'll stop being...

In David's defense business logic shouldn't be enforced by DRI. SQL Server provides constraints and triggers for this purpose.

Business logic and referential integrity should also not be confused. They do, however, provide powerful...

The optimizer mainly looks at the indexes, but you're right there can be positive performance as many db developers use the unique identifier as their PK\FK combinations and the PK usually...