RE: MultiMaster Replication

Chris/List
let me try to explain the problem i'm trying to solve.
1. 2 systems  same structure intially but  software upgrade done  seperately 
might cause  structures not to be in sync.
2. uptime requirements  for one node but not the other might cause the fact 
that we lose the  master definition site(network connectivity) while the other  
server is failed over to  a hot site.
3. there is transformation  happening  i.e sequences are different on both 
nodes.
4. the business does not want these system to be tightly coupled.
5. if the 2 systems are disconnected we  might need to change  information on 
any or both systems.

"Marquez, Chris" <cmarquez@xxxxxxxxxxxxxxxx> wrote:

>>1....there needs to be a  master definition site.
>>if the communication breaks between 2 sites 
>>will we have to change the master definition site.

It is possible to change the "master definition site", but generally this would 
only be done of the original master definition site is "gone", "dead", 
"lost"...temporary loss of one multi-master  site does not mean re-defining the 
master definition site...unless you need to do repadmin tasks that must be done 
for the (down) master definition site.

>>2...replicate sequences
I used local sequence on each side the would *not* collide buy using different 
START and INCREMENT values.

I liked Oracle Multi Master Replication for *simple* TABLE level replication 
where most or all transaction happen on one node...more than that and the admin 
of it (any transaction based replication) becomes painful.

hth

Chris Marquez
Oracle DBA



-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx on behalf of Fuad Arshad
Sent: Sun 8/21/2005 10:19 AM
To: oracle-l@xxxxxxxxxxxxx
Subject: MultiMaster Replication


I've been reading up on multimaster replication and had a few questions.

1. After the multimaster replication setup there needs to be a  master 
definition site.  if the communication breaks between 2 sites  will we have to 
change the master definition site.

2.  the tables the i'm trying to replicate have sequences that i need to 
transform to sequences  on the other side.

oracle seems to say its possbile  but i cant find an example.

If anyone on the list has had  experience with multimaster. if they could drop 
me an email and we could chat a little bit offline  that would be really great.

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