Hi folks,

So, yesterday I asked about this question and got a response. I had asked
if RAC would be an option for allowing a distant remote site to have fast
access to data. Obviously, I didn't have much of a clue about RAC. RAC
seems to indicate that you have multiple servers connected via a dedicated
wire to a central disk array. Since we cannot have this dedicated wire,
RAC won't work.

Unfortunately, I am getting questions from people who are not giving me
the entire story at one time, so I've been a bit confused about the
parameters of my questions here.

People are worried about network latency with a prospective remote site.
They feel that a DB server at the remote site, with the same data that is
here locally, is great because it eliminates network latency. OK, so
replication sounds like a possibility. But what is a reasonable
estimation for lag time between the primary DB and the replica. IE, do
you want fast access to slightly stale data, or slower access to fresh
data.

The other complicating factor, I just found out, is that this wouldn't be
just a replica thing. They would want the remote site to be able to
interact and change data in the DB. So, changes would have to flow in
both directions, from primary to replica and replica to primary. Is this
possible?

I guess, in theory, they could request data from their local replica, but
changes would be sent back to the primary DB and not made on the local
replica. But, that then begs the question, if they make a change on the
primary, how long will it take before the change gets back to their
replica?..

Does any of this make sense? My apologies for my confusion on this issue.
Just lack of experience with the "not day to day" db stuff that I usually
deal with.

Thanks very much for any assistance.


--
Blue skies.
Dan Rossi
Carnegie Mellon University.
E-Mail: [Email Address Removed] (412) 268-9081
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