Changed data management
It's all very well replicating data in real-time between a source and target database, but what if something disastrous happens to the source data; a user drops a table or deletes important records or the data becomes corrupt? The answer maybe to build a delay into the changed data delivery but this seems to defeat the object of fast data replication. What can be done to manage the changed data, ensuring that only the valid transactions succeed?
There are a number of solutions to this problem, none of which prevent user error or data corruption. Let's now take a look at some of these, which are provided by the Oracle database.
Point in Time Recovery (PITR)
Since Oracle 10g, the database provides "flashback" technology allowing the database, a table or even a transaction to be flashed back to a SCN or timestamp. The Flashback technology provides a fast reliable recovery mechanism over the traditional method of performing a point in time recovery.
