Re: IBM Debunks Oracle's MultiVersion Read Consistency ?

"Robert Allen" <rallen_at_NOSPAMOKhgi.com> wrote in message news:b_yoa.380076$HU.52078_at_news.easynews.com...
> http://www-
> 3.ibm.com/software/data/pubs/papers/readconsistency/readconsistency.pdf

I also should have mentioned that "running out of space=canceled transaction" in not necessarily true in 9i, the feature that may negate this is resumable space management, though I'd be fairly suspicious of the effect of resumable space management on a transactional app.

You also ask what the advantages of MVRC are, they are at least the following.

1. Far less serialization
2. Readers don't block writers and vice versa.
3. You get a space management rather than a lock management overhead.
4. You don't get to wait for wrong answers if readers and writers are accessing the same table.
5. Flashback query
6. Database transactions can map one to one to business transactions.

--
Niall Litchfield
Oracle DBA
Audit Commission UK