Oracle Distributed Systems

DBMS_OFFLINE_SNAPSHOT: Performing Offline Snapshot Instantiation

The DBMS_OFFLINE_SNAPSHOT package allows you to instantiate snapshots without having to run the CREATE SNAPSHOT command or the DBMS_REPEAT.SNAPSHOT_REPOBJECT procedure over the network. Doing offline instantiation in this way is particularly useful in cases in which you wish to instantiate a snapshot site with a large amount of data in an advanced replication environment. Offline instantiation refers to the population of snapshots with the import and export utilities, as opposed to using the DBMS_SNAPSHOT.REFRESH procedure. This technique is less time consuming and less taxing on your network, and it minimizes the time your environment must be quiesced.

How the Package Is Used

The following table summarizes the steps you follow when using DBMS_OFFLINE_SNAPSHOT:

Step	Where Performed	Activity
1	Master site	Create snapshot log on table(s) to be snapshotted (optional, but recommended).
2	Master site	Create a snapshot locally on the table(s) to be snapshotted.
3	Master site	Export SNAP$_table_name table(s) created in Step 2 as the schema owner.
4	New snapshot site	DBMS_REPCAT.CREATE_SNAPSHOT_REPGROUP.
5	New snapshot site	DBMS_OFFLINE_SNAPSHOT.BEGIN_LOAD.
6	New snapshot site	Import SNAP$_table_name tables from export file created in Step 3.
7	New snapshot site	DBMS_OFFLINE_SNAPSHOT.END_LOAD.
8	Master site	Drop snapshot(s) created in Step 2.

Installation and Access

The DBMS_OFFLINE_SNAPSHOT package iscreated when the Oracle database is installed. The ...