Wednesday , April 24 2024

Flashback Data Archive

Flashback Data Archive historically stores changes in the database for a retention period determined at the table level.

Data at the desired moment is retrieved with Flashback Query or Flashback Versions Query.

It works at the table level, UNDO works much more effectively without reaching this result by setting the size of TABLESPACE too large.

The working principle is as follows.

Once activated, the FBDA background process is created.

FBDA captures the changing data from UNDO and Buffer Cache every 5 minutes and writes it to the FDA1 table.

Its management is done entirely internally.

The FBDA process can create up to 10 slave processes when necessary.

It automatically purges old data when the retention period comes.

If the OPTIMIZE DATA clause is used, the data is kept compressed and deduplicated.

Historical Data is kept in a partitioned manner. At least 1 day and 1 MB.

If FBDA and Slave processes are too busy, the user’s response time will slow down.

By default, collection_level is NONE. It can also be TYPICAL and ALL.

When it is TYPICAL, information such as DB User ID, Global User ID, Client Identifier, Service Name, Module Name, Host is also kept.

It has DDL support.

ADD, DROP, MODIFY, RENAME column
DROP and TRUNCATE partition
RENAME and TRUNCATE table

Loading

About Onur ARDAHANLI

Leave a Reply

Your email address will not be published. Required fields are marked *

Categories