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Re: Question on asynchronous data propagation from a local to the central oracle database

From: Bhooshan Prabhu <>
Date: 2 Jul 2002 21:50:20 -0700
Message-ID: <>

Thanks Pete,

One more doubt. Is it an absolute must to use the Oralce replication manager tool to configure the replication environment, replication groups, objects etc.


Pete Sharman <> wrote in message news:<>...
> In article <>,
> says...
> >
> >Hello,
> >
> >I am in the process of evaluating various methods for propagating data
> >from a local Oracle database to a central Oracle database. Oracle
> >version is yet undecided but it would either be Oracle 8.1.7 (I know
> >it gets desupported by December 2003) or Oracle 9i on Solaris m/c.
> >
> >The local database that I refer to, would be a database located in
> >offices located at geographical locations that offer poor
> >infrastructure and network bandwidths. The number of local databases
> >could be up to 150-200.
> >
> >The central database shall be 1 and shall be used by users from
> >offices that are in developed countries that offer good network
> >bandwidths. Thus, both the central as well as the local database can
> >be in use by different set of users at the same time.
> >
> >The users would be accessing both these databases over web based
> >applications.
> >
> >The requirement is that the data that gets added / modified / deleted
> >at the local database site should be propagated to the central
> >database but, in an asynchronous mode.
> >
> >I have read about data replication methods provided by Oracle. I've
> >the following queries.
> >1. Would it be possible to replicate data off a table from a local
> >database to
> > the central database while the table at the central database itself
> >might be
> > getting its own data from users? i.e. Table A is being inserted
> >into in the
> > local database at site A. Oracle replication shall try and
> >propagate the
> > insert to central site C. At that moment, a user B might be
> >inserting data
> > in the table A at central site as well. Would replication work when
> >the table
> > at the master site would also be active? I guess yes but, need
> >confirmation
> > from some one..
> Yes. Otherwise multi-master replication or master-updatable snapshot
> replication would not work.
> >
> >2. The data from the local database needs to be available at the
> >central site
> > in near real-time but, not real-time. I gather that the jobs to
> >replicate
> > data from the local to the central database shall get executed at a
> >certain
> > frequency. Can this frequency be set to 1 minute? Is anyone aware
> >of any
> > repercussions if the frequency is kept so low?
> I tend to not go below 5 minutes because then the overhead of checking whether
> there are rows to move or not MAY cause a performance issue. Note the MAY is in
> uppercase because you can't confirm this till you do quite a bit of testing.
> However, near real-time may not be possible for you anyway if there are network
> problems like you stated earlier.
> >
> >3. I can also think of Oracle advanced queues as another Oracle
> >technology
> > offering that could prove useful to carry out the data propagation
> >from the
> > local to the central site. How reliable is Oracle AQ in terms of
> >stability,
> > robustness and maintainability?
> Replication uses the AQ technology anyway.
> >
> >4. The application shall be developed using Java and shall get
> >deployed at both
> > the central as well as the local sites either using a Web server or
> >Apps
> > server. EJB 2.0 specifications do specify message driven beans. I
> >feel that
> > the data propagation can also be carried out using JMS and the
> >message
> > driven beans. Any feedback on this thought?
> Never tried this apporach so I can't comment.
> >
> >Regards
> >Bhooshan
> HTH. Additions and corrections welcome.
> Pete
> SELECT standard_disclaimer, witty_remark FROM company_requirements;
Received on Tue Jul 02 2002 - 23:50:20 CDT

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