Oracle 12 R 2 Database Flashback Technologies Hariprasath

Oracle 12 R 2 Database Flashback Technologies Hariprasath Rajaram

Today’s Agenda

History of Oracle Flashback Technologies

Flashback Technologies Transformation Since V 9 § § § § Flashback Query using AS OF scn/timestamp Session Level Flashback using dbms_flashback Statement Level Flashback using AS OF clause Flashback Version Query Flashback Transaction Query Flashback Table Flashback Drop Flashback Database § Flashback Transaction § Flashback Data Archive (Total Recall) § Flashback Standby Database § Multitenant : Flashback Pluggable Database (PDB) Temporal Validity §

Flashback Architecture Overview

Flashback Technologies Features § § § § § Flashback Query Flashback Table Flashback Drop Flashback Versions Query Flashback Transaction Query Flashback Query Functions Flashback Database Flashback Data Archive Flashback Pluggable Database (PDB) Temporal Validity

Flashback Advanced use cases Flashback technology is integrated into Oracle Recovery Manager (RMAN) and Oracle Data Guard. So, apart from the basic use cases mentioned above, the following use cases are addressed using Oracle Flashback. Block Media recovery by RMAN - to perform block level recovery Snapshot Standby - where the standby is temporarily converted to a read/write environment for testing, backup, or migration purposes Re-instate old primary in a Data Guard environment – this avoids the need to restore an old backup and perform a recovery to make it a new standby. Guaranteed Restore Points - to bring back the entire database to an older point-in-time in a guaranteed way.

Flashback Architecture Overview Type Name Purpose Example Scenario Investigat ion/ Correctio n Flashback Query To query a table for a value at one previous point in time verify the value alter batch update Replace the latest value of a column will a value as of 10 AM Investigat ion Flashback Version Query To query the changes that occurred in a table UNDO between two points in time Monitor stock inventory quantity changes during the past day Obtain the transaction that changed the value Investigat ion Flashback Transaction Query To query the details of the transaction To determine who initiated the transaction and the values affected

Flashback Architecture Overview Type Name Purpose Example Scenario Correctio n Flashback Table To rewind the table content to a point in time A few rogue update statements incorrectly updated multiple rows in the table. Those updates need to be reversed Correctio n Flashback Drop Undelete a dropped object User accidentally dropped a table that needs to be restored Correctio n Flashback Transaction Reverse a transaction To reverse a transaction that updated a few tables CDP Flashback Database Rewind the entire database to a previous point in time User truncated a few important tables that need to be restored