Databases Reference
In-Depth Information
Anytime you restore your database with a backup control file or perform an incomplete database recovery, you
are required to use the
alter database open resetlogs
command to open your database. This resets the online
redo log sequence to 1 and creates a new version of your database. Oracle calls this fresh version of your database a
new incarnation.
You can view incarnation information by querying the V$DATABASE_INCARNATION view. You can also view
database incarnation data from within RMAN by issuing the following:
RMAN> list incarnation of database;
In rare situations, you may find that you need to restore to a previous incarnation of your database. For example,
there may be data that is contained only in a prior incarnation, and the only way to retrieve it is to restore and recover
to that previous incarnation of your database. The key here is that when you restore and recover to a prior incarnation,
you need to ensure that the control file that you restore is aware of the particular database incarnation that you want
to restore.
Performing Tablespace Point-in-Time Recovery
Problem
A rogue developer thought he was in a test environment and issued commands to delete data from several tables in
one tablespace. It turns out he was in the production environment. You want to use tablespace point-in-time recovery
(TSPITR) to restore your tablespace to the point in time just before the erroneous DML was issued.
■
Before using TSpiTr, consider other forms of recovery, such as flashing back a table to before drop or before an
SCn, or restoring a single table. See Chapter 13 for full details.
Tip
Solution
This recipe shows how to perform fully automated RMAN tablespace point-in-time recovery. Here are the steps:
1.
Determine the time to which you want to perform TSPITR.
2.
Determine and resolve any dependencies to objects in tablespaces not included in
the TSPITR.
3.
Determine whether there are objects that will not be recovered.
4.
Create a destination on disk to temporarily hold the auxiliary database.
Run the
recover tablespace until
command.
5.
6.
Back up the restored tablespace and alter it online.
Step 1: Determine the Time to Perform TSPITR
You need to decide what time or SCN to which you want to restore the tablespace. In most scenarios this will be just
prior to the point at which the erroneous drop or delete was issued.
