DBMS_OFFLINE_OG: Performing Site Instantiation

When you add a new site to your replicated environment, you must not only create the replicated objects but also populate snapshots and replicated tables with a copy of the current data. Although you can set the copy_rows parameter to TRUE in your call to the DBMS_REPCAT package’s CREATE_MASTER_REPOBJECT or ADD_MASTER_DATABASE procedure, this option is not practical for schemas that are large or complex.

The DBMS_OFFLINE_OG package provides a more feasible method of site instantiation. The general idea is that you export data from an existing master site and import it into the new master site. While the import is taking place, the existing master site’s queue data updates to the new site, but the updates are not actually sent until the load is complete. This package lets you perform much of the instantiation without quiescing the entire replication group.

How the Package Is Used

The following table summarizes the steps you follow when using DBMS_OFFLINE_OG.

Step

Where Performed

Activity

1

Master definition site

DBMS_REPCAT.ADD_MASTER_DATABASE

2

Master definition site

DBMS_REPCAT.SUSPEND_MASTER_ACTIVITY

3

Master definition site

DBMS_OFFLINE_OG.BEGIN_INSTANTIATION

4

Any master site

Export replicated schema

5

Master definition site

DBMS_OFFLINE_OG.RESUME_SUBSET_OF_MASTERS

6

New site

DBMS_OFFLINE_OG.BEGIN_LOAD

7

New site

Import data from Step 4

8

New site

DBMS_OFFLINE_OG.END_LOAD

9

Master definition site

DBMS_OFFLINE_OG.END_INSTANTIATION

Installation and Access

The DBMS_OFFLINE_OG ...

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