Thanks Will.  I can't believe it, but you are making me go out and buy that book!  <g>

If the book clears up my misunderstanding, that will be great.  But I...

Excellent post Paul. Snapshot isolation is useful for a consistent (but not up to date) result without locking. RSCI is logically equivalent to MVCC which has the same drawbacks.

Thanks for...

On what grounds? 

Uh, because the data is right, and the implementation is right.

You set up a straw man, where this condition applies, and you don't care about this, and...

Great discussion, which brings out on of the most important truisms in database processing - maintaining data integrity and concurrency is really, really hard if you want both.  It still...

Actually, if you are talking about a database enforced technology solution, the answer is multi-version read consistency, pioneered by Oracle and used by others.  Snapshot isolation will give you a...

There is an aspect covered in your article that I think is praise-worthy - the "correctness" of data can only be decided by stakeholders.  If the stakeholders make an informed...

This could be an exception, but as a general rule, disk replication does not allow for data integrity for database without gaps in data integrity protection.  The first is that...

No problem - I just took some exception to some of the language, based, I am sure, on decades of trying to get people to understand this.  Showing a NULL...

Nick, I think that technically, NULL does in fact mean unknown.  Both TRUE = NULL and FALSE = NULL are evaluated as false.

Sorry, but you said it again.  You imply that NULL is not meaningful.  It is, and it has a very specific meaning in three state logic.  If you use three...

• This reply was modified 3 years, 11 months ago by  rick-1071254.

I agree with Nick, but let's go even father.  NULL is not a meaningless value.  NULL indicates a valid state in three state logic.  To simply replace it with some...

The truly sad part about this discussion is the lack of understanding of data integrity and consistency.  Sigh.

This is getting tiring.

Except snapshot isolation does not automatically do what you say as it operates on an individual statement level.  So each subsequent query might still use different data.

Yes,...

Snapshot Isolation doesn't let you for example just write a query where you can say show me the query based on the data from 10 minutes ago.

I don't know snapshot...

Do you expect your bank account to be locked while you page through your transaction history?

Not if I am the only one accessing it, which is exactly what multi-version consistency...