Just use Data Guard and dont complicate your life with replications! Thanks -- LSC On Mon, Aug 11, 2008 at 10:29 PM, Pradeep Chetal < Pradeep.Chetal@xxxxxxxxxxxxxx> wrote: > > Yavor, > > If we are OK with few hours of delay between the 2 sites, is there other > software that works to keep the 2 sites in sync? > > Some folks I talk to, do NOT like Oracle Advanced Replicatiom. > > What about Golden Gate software or IBM's Data mirror? > > -- Pradeep > > -----Original Message----- > From: Yavor Ivanov [mailto:Yavor_Ivanov@xxxxxxxx] > Sent: Friday, August 01, 2008 6:57 AM > To: Pradeep Chetal > Cc: oracle-l@xxxxxxxxxxxxx > Subject: RE: Oracle MAA and active-active replciation between site > > > The big concern about the application in replication environment > are the conflicts. > - You should in all ways avoid updating or deleting the same row > of a table from both sites at the same time. > - The same for the inserts. Your application should not be able > to insert rows with the same primary key values from both sites. E.g. if > you have primary keys generated by sequence, one of the sites should > start with 1 increment by 5 and the other will start with 2, increment > with 5. > - You must have primary key on all tables. This is not mandatory > from the docs, but it is always good practice, even without replication. > - You should design all triggers carefully - when there is an > insert in a table on one site, the trigger may make some things like > inserting/updating/deleting on other tables. Then when this is > replicated to the other site, there will be insert again, but the > trigger should not fire again. > - When there is a conflict, a whole transaction is not > replicated. Even if you do not care for this problematic row in this > table, a conflict on a row of a table will block the whole transaction > and you have to resolve it. > - If you decide to let the replication of all following > transactions be done in spite of the conflicts, you may have lots of > anomalies in the data. In the other hand, resolving a conflict may take > some time and you may not want to block the whole replication because of > a single problematic transaction > > Regards, > Yavor Ivanov > Oracle Certified Master > > > -----Original Message----- > From: Pradeep Chetal [mailto:Pradeep.Chetal@xxxxxxxxxxxxxx] > Sent: Friday, August 01, 2008 12:56 PM > To: Yavor Ivanov > Subject: RE: Oracle MAA and active-active replciation between site > > > Yavor, > > In terms of wise application design, what do you recommend? > > What are the big 3-4 things we should worry about? > > -- Pradeep > > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Yavor Ivanov > Sent: Friday, August 01, 2008 3:05 AM > To: Pradeep Chetal; oracle-l@xxxxxxxxxxxxx > Subject: RE: Oracle MAA and active-active replciation between site > > > I've done one project active-active replication using oracle's > Advanced replication. There is good documentation about this. > There are 2 basic problems with this > - The conflicts. You will always have conflicts on > active-active replication. Most of them can be avoided by wise > application and process design, but it will need lot of thinking. And > you will still have conflicts you cannot avoid and cannot resolve > automatically > - The burden. It is much harder for administration. > Adding a simple column is pain in the ass, Yes, there are procedures, > but still... It is hard. > But it really works - for 2 years now. I would consider this. > > I also have done it with "Basic replication", master - > (updateable) mvews with 12 active sites across the country (one master > in HQ). But it is even harder to support this than Advanced replication. > And the application on this project was specially built with the > replication in mind. It works for 9 years now (we started it on 8.1.5, > now all the servers are 10.2). But I would never advise this approach, > this is aged and arcane thing. > > Regards, > Yavor Ivanov > Oracle Certified Master > > -----Original Message----- > From: oracle-l-bounce@xxxxxxxxxxxxx > [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Pradeep Chetal > Sent: Thursday, July 31, 2008 6:18 PM > To: oracle-l@xxxxxxxxxxxxx > Cc: Pradeep Chetal > Subject: Oracle MAA and active-active replciation between site > Importance: High > > > > Hi, > > Oracle has an MAA with > > http://www.oracle.com/technology/deploy/availability/pdf/MAA_WP_10gR2_Ro > admap.pdf<http://www.oracle.com/technology/deploy/availability/pdf/MAA_WP_10gR2_Roadmap.pdf> > > However, one of our clients would like to have active-active replication > between remote sites, so that each site can be used. > > Have you done this? What software did you use? > > Also, what are the limitations on schema, if any to do this? > > Thanks in advance, > > -- Pradeep > > > > > Pradeep Chetal > Sr. Director - Infrastructure Architecture > > > > Mformation Technologies Inc. > Switchboard: +1 732 692 6200 > > > > Visit WWW.MFORMATION.COM and see how the MFORMATION SERVICE MANAGER can > help you to transform your business > > > Please consider the environment before printing > -- > //www.freelists.org/webpage/oracle-l > > > -- > //www.freelists.org/webpage/oracle-l > > > > > > Visit WWW.MFORMATION.COM and see how the MFORMATION SERVICE MANAGER can > help you to transform your business > > > Please consider the environment before printing > > > > Visit WWW.MFORMATION.COM and see how the MFORMATION SERVICE MANAGER can > help you to transform your business > > > Please consider the environment before printing > -- > //www.freelists.org/webpage/oracle-l > > >