oracle replication - help (urgent)

[Jennifer]

Hi,
I have 2 questions about how Oracle implements replication.
1 - On Updateable Materialized Views, how does the Fast Refresh implements changes? Does it replicate sql commands to the MVs or does it use a different method, sending only the changed info, like SQL-Server's Merge Replication?
2 - Does Oracle9i implement a workflow model? That'd be a model where only one site can update at a time, but this site is changeable - for example, a Read Only Materialized View site can request an update for the master site, becoming the temporary master and making the update - thus avoiding any inconsistency of data but allowing MV sites to make updates.
Thanx a lot for any help, it's pretty urgent.

[gbrabham]

For Mat. Views, only the changed columns and the rowid or primary
key (however it was setup) are sent for update. Not the entire
column nor the SQL statements ....

Can't speak for 9i and workflow model...

Gregg

[Jennifer]

So, it'd be a type of Differential Replication, right? Sort like Merge Replication?
And it's a different mechanism comparing to Multimaster Asynchronous? (as it seemed to me, on MM As. the DML statements are sent, is that correct?)
Thanx a lot, Gregg.

[gbrabham]

With Snapshot replication....
The snapshot site pushes changes to the Master (as often as
setup in the "push" job. It request changes FROM the Master
as often as the "refresh" job. Only column changes are sent...
The MASTER site NEVER pushes changes to the Snapshot site.

In MultiMaster - All sites push and pull changes as often
as their jobs are scheduled ... Again ... only the changes are
sent....

Multimaster can be set up as more of a Transactional replication
with "Pushes" and "Pulls" both occurring from all Master Sites.

Gregg

[Jennifer]

So, Multimaster can be either Transaction or Differencial?
The doubt comes from here:

Asynchronous replication independently propagates any DML or replicated procedure execution to all of the other master sites participating in the multimaster replication environment. Propagation occurs in a separate transaction after the DML or replication procedure has been executed locally

This was taken from the online docs, in the Multimaster Replication / Asynchronous Replication topic.

Thanx again.

[manodba]

It can be either way depending on how replication is setup.
Synchronous replication is transactional but requires a very highly available and high speed network.
Asyncrnous replication propogates changes at scheduled intervals but conflicts are possible.

-Mano

[vinodkmg]

Hi,
Oracle 9i??? try using ORACLE STREAMS as replication solution.

Regards,
Vinod

[julian]

Originally posted by manodba
It can be either way depending on how replication is setup.
Synchronous replication is transactional but requires a very highly available and high speed network.
Asyncrnous replication propogates changes at scheduled intervals but conflicts are possible.

-Mano

The better option is synchronous replication but network latency seldom gives us the chance to implement this. I administer asynchronous multimaster replication where one needs to take good care of the replication conflicts.

[Jennifer]

Thanx a lot for your help, but you're missing the point of my question.
What I need to know is what information is sent on refresh/synchronization process. For example, on Procedural Replication, what is sent is a call to a replicated stored procedure.
I need to know if on Updatable Materialized Views and Multimaster Replication what is sent is the SQL/DML statements that were applied on the remote site or just the necessary info (f.e. the primary keys and updated cols) like what's done on SQL Server's Merge Replication.
Thanx again,
Jen

[stmontgo]

http://download-west.oracle.com/docs...view.htm#12432

Procedural replication replicates only the call to a stored procedure that an application uses to update a table. It does not replicate the data modifications themselves.