Re: Differences between Oracle,DB2,SQL2005 in cost estimation

From: Steven <songxin328_at_gmail.com>
Date: 21 Apr 2007 01:19:30 -0700
Message-ID: <1177143570.222386.324520@n76g2000hsh.googlegroups.com>

Yeah, actually, I mean the cost based optimization. I think in general they were based on System-R model in calculating the execuation cost.
that is: Total cost = i/o cost + cpu cost

but Is there anything different when to implement this formula? I read this article below
Cost Control: Inside the Oracle Optimizer and I am looking for similar articles about other dbms...

---

Anyway, 3x for your reply~

Carl Kayser wrote:
> "Steven" <songxin328_at_gmail.com> wrote in message
> news:1176977151.318652.95400_at_b75g2000hsg.googlegroups.com...
> > Anybody knows this?
> > Thanks a lot.....
> > orz~
> >
>
> 43
>
>
> In all seriousness your question is near the level of "What is the meaning
> of life?" What do you mean by cost? License cost? Site license cost (for
> how many servers with how many CPUs, etc)? Over what time span? Or perhaps
> you are asking about cost based optimizers?
Received on Sat Apr 21 2007 - 03:19:30 CDT