Re: tx isolation

"Brian E Dick" <bdick_at_cox.net> wrote in
news:4KJG9.65122$wc2.2718284_at_news2.east.cox.net:

> One of the biggest shortcomings of the TPC-C benchmark is its "shared
> nothing" architecture. It allows you to infinitely scale the benchmark
> without concern for resource contention.

I think you might be misusing the term "shared nothing" ... I think you're intending to say that the TPC-C is a highly partitionable problem. Is that correct?

I don't agree with this assertion ... take a look at the 'payment' transactions for an example of where interactions _must_ happen. Or perhaps you can tell me how the payment transaction can be implemented in a highly partitioned manner. I don't see it.

> By side-stepping the locking issue, this benchmark gives the SQL
> Server locking model an unfair advantage over the Oracle locking
> model. In a real world "shared something" or "shared mostly"
> application, Oracle shines.

I believe this assertion is incorrect because the first statement was wrong that the benchmark is a highly partitionable problem. The payment transaction clearly shows that we need to coordinate the updates to the affected tables among the clients.

> Also, multiversioning does not make for lazy
> developers.

This one is subjective ... I should have said, "In my experience ..."

> Multiversioning resolves a difficult problem, resource
> contention, and allows the developer to move on to bigger and
> tougher problems.

There's nothing difficult about working with a locking model.

In general, all DBMS have their nuances and every database developer/dba must be responsible to learn them. How many times have people posted the same question to this newsgroup without having taken the time to read the docs? Same point is made with a locking model. It's easy to work with and if people spent a sliver of time to read it, they wouldn't wedge themselves ... as when people wedge themselves with improper RBS configuration.

-- 
Pablo Sanchez, High-Performance Database Engineering
http://www.hpdbe.com