Re: Concurrency in an RDB
Date: Fri, 8 Dec 2006 08:59:11 -0000
Message-ID: <2rWdnfYdR4n_tOTYRVnyvwA_at_pipex.net>
"David" <davidbl_at_iinet.net.au> wrote in message
news:1165564572.553799.62710_at_f1g2000cwa.googlegroups.com...
> Bob Badour wrote:
> I don't have the RDB experience to know how often and to what extent
> dead-lock seriously degrades performance. However, I have heard of
> real cases where repeated dead-lock kills performance.
Since you claim not to be a DB programmer I want to make sure I share the understanding of the words you're using here--and there are loads of DB programmers who use the same words and get it wrong.
When you say "deadlock" do you mean a deadly embrace, in which no transaction can terminate even in principle? Or do you mean a prolonged wait for a lock?
In principle a deadlock needn't cause a performance problem. It can, in principle, be detected quickly and resolved quickly. On the other hand a prolonged wait for a lock is just that. (Though I've seen the ghastly term "livelock" used to describe it!)
Roy Received on Fri Dec 08 2006 - 09:59:11 CET