Re: computational model of transactions

Brian Selzer wrote:
> "J M Davitt" <jdavitt_at_aeneas.net> wrote in message
> news:BZjBg.56521$u11.18671_at_tornado.ohiordc.rr.com...

[snip]

>>Holy bat, Crapman! "As an aside" you've either abandoned
>>the points you made earlier in this thread or have been
>>using terminology inconsistently.  When you started with

> So the discussion diverged. I think it was you who introduced the system
> into the argument, not me.

"Diverged?" I don't think so. Besides an response to a post from Marshall, all my posts to this thread have been made trying to get clarification on points in your writings.

You think *I* dragged "the system" into the argument? No way. Consider:

• How can any discussion of the computational model of transactions avoid a system?
• How do "other intervening transactions" exist without a system?
• What was that "the system can tell the difference" all about?

> My original argument is that there is a
> difference in semantics between replacement and modification, and that that
> difference can affect concurrency.

I gathered that from

   Modification depends on the current state of the    attribute; whereas replacement doesn't.

and:

   I disagree with the idea that the entire    transaction needs to be isolated or serialized.

But, then, this seems out of place:

> Whether any implementation is involved
> or not doesn't change that, nor have any of the statements I've made been at
> odds with it.

> I noticed the divergence of the discussion in the last post,
> so I thought I'd try to bring it back on track with the aside. I certainly
> didn't expect to be tarred and feathered as a result.

If you're being tarred and feathered, it' not because you were bringing the discussion back on track.

Speaking of which:

[snip]

>>I was about to move on to the question, "If the
>>system can detect that a 'replacement' UPDATE is
>>in the mix, why not require it to optimize the
>>workload and discard all the 'modify' UPDATEs?"

Or is discussion of a system off-track? Received on Sun Aug 06 2006 - 23:26:48 CEST