On 11/14/2010 02:38 AM, Mladen Gogala wrote:
> Craig Ringer wrote:
>> It sounds like you're describing Oracle-style MVCC, using redo logs.
>>
>> http://blogs.sybase.com/database/2009/04/mvcc-dispelling-some-oracle-fudunderstanding-the-cost/
>>
> Craig, this is an interesting blog page, making some valid points about
> the multiversioning vs. locking. The ATM example, however, is
> unrealistic and couldn't have happened the way the author describes.
Yep, you're quite right. I was using it for its explanation of some of
the costs of MVCC as Oracle implements it, because it's surprisingly
hard to find explanations/analysis of that with some quick Google
searching. I hadn't read beyond that part.
I'd be really interested in some *good* writeups of the costs/benefits
of the various common mvcc and locking based rdbms implementations.
Thanks for posting a breakdown of the issues with that article, lest
others be mislead. Appreciated.
--
Craig Ringer