Document ID:    1020699.6
Subject:        Replication Option Enhancements in Version 7.3  
Author:	        Unknown
Last Modified:  Unknown 


 
This bulletin summarizes the enhancements, obsolete procedures and new and 
changed procedures seen in the advanced replication option in Oracle 7.3 
server release.   
 
 
Enhancements 
 
Oracle7 Server Release 7.3 contains following major enhancements to the 
advanced replication option: 
 
1)  TABLE COMPARISON: 
 
The DIFFERENCES and RECTIFY procedures can be used to maintain the data 
consistency among the replicated tables.  The DIFFERENCES procedure is used to 
identify any discrepancies in the table at 2 sites.  RECTIFY procedure is then 
used to resolve the differences and bring the 2 tables to a consistent state. 
 
2)  OBJECT GROUPS: 
 
A group can span multiple schemas thereby eliminating the need to replicate a 
schema.  For example table EMP from SCOTT's schema can co exist with table 
DEPT from AMY's schema in a group and the group can be replicated.  However, 
object can belong to just one group. 
 
3)  SYNCHRONOUS DATA PROPAGATION: 
 
It is now possible to propagate synchronously whenever one needs to do so and 
then can switch back to asynchronous mode.  When the propagation mode is 
synchronous, the only asynchronous operation will be the refresh of snapshots. 
 
The procedure which is used for switching propagation modes is 
ALTER_MASTER_PROPAGATION. 
 
4)  OFFLINE INSTANTIATION: 
 
 
In earlier versions, if a new site had to be added to the replication 
environment, the existing sites in the environment had to be in quiesced state 
for the entire duration of adding process.  Now with this option, the time the 
other sites need to be in quiesce mode is considerable low. 
 
Using this option, all the sites in the environment is quiesced.  The new site 
is added.  All other sites are then brought back to normal state.  And then 
the data is made consistent just by working on the new site.  In addition to 
this the other advantage is the network is not overworked during this 
operation. 
 
The mode used in offline instantiation is asynchronous. 
 
5)  CONNECTION QUALIFIERS: 
 
It is now possible to have several database links of the same type pointing to 
the same remote database but establishing the connections via different 
communication pathways including ethernet, modem etc. 
 
REFERENCES: 
Oracle7 Server Distributed Systems: Volume II Replicated data, Release 7.3.