Snapshot with update on both sides

Question

Hi,
I've created a snapshot with the for update clause, but when I
use the dbms_snapshot.refresh procedure, the server looses
everything made in the point B.
Point A -> master
Point B -> snapshot
Sequence:
1) Create a simple table in the master an populate it
2) create snapshot log on master
3) create database link on B to A
4) create snapshot on B
5) update the table on A
6) dbms_snapshot.refresh on B =====> ok!!!
7) update the table on A and on B
8) commit on A and B
9) dbms_snapshot.refresh on B ===> the server just applies the
changes made in A, it looses the changes in B
I need help.
Best regards,
Ari
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Answer 1

Ari Arantes (guest) wrote:
: Hi,
: I've created a snapshot with the for update clause, but when I
: use the dbms_snapshot.refresh procedure, the server looses
: everything made in the point B.
: Point A -> master
: Point B -> snapshot
: Sequence:
: 1) Create a simple table in the master an populate it
: 2) create snapshot log on master
: 3) create database link on B to A
: 4) create snapshot on B
: 5) update the table on A
: 6) dbms_snapshot.refresh on B =====> ok!!!
: 7) update the table on A and on B
: 8) commit on A and B
: 9) dbms_snapshot.refresh on B ===> the server just applies the
: changes made in A, it looses the changes in B
: I need help.
: Best regards,
: Ari
Ari,
You need to generate replication support for the updatable
snapshot using the dbms_repcat.create_snapshot_repobject
procedure.
2 way replication is pretty complex to set up. You will need
correctly configured database links, snapshot logs at the master
site and replication support for all your updatable snapshots at
the snapshot site.
There are quite a few ways of setting up updatable snapshot
replication. My best advice is to get hold of the "replication
bible" from Oracle Documentation.
Oracle7 Server Distributed Systems Replicated Data or equivalent
for 8. This is essential.
good luck,
Dave.
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