Re: Options for wide-area database?

ernestsiu_at_yahoo.com (Ernest Siu) wrote in message news:<2833144d.0402171234.32b13e6f_at_posting.google.com>...
> I don't think RAC can be set up with async.

Of course not. From definition of async is clear that you can't get guaranted writes with this setup.  

> > Real Application cluster can be deployed on distance let say up to 15
> > kilometers. And because you were talking about problems with latency,
> > I can tell you that we have achieved ms latencies with gigabit
> > capacities on thirty kilometers distance. So no big deal here.
>
> Like your experience, I believe with 100km in a metro environment is
> do-able because the latency is very low. But I'm thinking about RAC
> over hundreds to thousands of kilometers.

I've done a guite deep research in this area and more than 15 kilometers is still a no-no for RAC. I've asked Oracle for oficial statement, I've asked independend experts, going futher with distance posses too much risk in enteprise environment. In RAC low latencies are the key for success, bandwidth is no problem, but latencies definitely are.

--
Dusan Bolek

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