Can we have a Snapshot log for a Snapshot insted of a Table

[srinivast]

Hi,

Can we create a snapshot log on a snapshot. If we create, Does the snapshot log that is created on a snapshot records all the changes made to the snapshot.

Ex: 1) I have a table A.

2) Create the snapshot log for A.

3) create a snapshot B for A.

4) Create the snapshot log for B.

5) Update a record in the table A.

6) Snapshot log for A is recorded the changes made to A.

7) Apply the FORCE Refresh on the snapshot B.

8) The snapshot B is updated with the modified data.

So, there is a change in the data on the snapshot B. But, there are no changes recorded in the snapshot log that is created for B.

so, I am interested in knowing, what the oracle says for this scenario. I am not able to find this information in the Oracle documentation. Can any body tell me, whether is it possible to record the changes that are made to snapshots like (B) in my example.

--Srinivas.

[Goochable]

What version of the database?
Have you looked at Materialized Views
with fast refresh?

[srinivast]

I am working on the 8.1.7 version, basically the snapshot and the materialized views are the synonyms to each other.

[mallika]

Hello Srinivas:

Before u apply FORCE Refresh of ther snapshot, the snapshot log will contain data. Once snapshot is refreshed snapshot log will be null (zero records). So to view what it contains, u must do before refresh. It is the log of events between refresh not a repository to store all the data again, which will be replica of the snapshot.