OCP 1Z0 053 130

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130.Which are the prerequisites for performing flashback transactions on your database? (Choose all that
apply.)
A. Undo retention guarantee for the database must be configured.
B. Supplemental log must be enabled for the primary key.
C. Supplemental log must be enabled.
D. Execute permission on the DBMS_FLASHBACK package must be granted to the user.
Answer: BCD

http://docs.oracle.com/cd/E11882_01/server.112/e25494/undo.htm#ADMIN11463

Retention Guarantee

To guarantee the success of long-running queries or Oracle Flashback operations, you can enable retention guarantee. If retention guarantee is enabled, the specified minimum undo retention is guaranteed; the database never overwrites unexpired undo data even if it means that transactions fail due to lack of space in the undo tablespace. If retention guarantee is not enabled, the database can overwrite unexpired undo when space is low, thus lowering the undo retention for the system. This option is disabled by default.

http://docs.oracle.com/cd/E11882_01/appdev.112/e41502/adfns_flashback.htm#ADFNS1008

Configuring Your Database for Flashback Transaction

To configure your database for the Flashback Transaction feature, you or your database administrator must:

With the database mounted but not open, enable ARCHIVELOG:
```
ALTER DATABASE ARCHIVELOG;
```
Open at least one archive log:
```
ALTER SYSTEM ARCHIVE LOG CURRENT;
```

If not done, enable minimal and primary key supplemental logging:

ALTER DATABASE ADD SUPPLEMENTAL LOG DATA;ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (PRIMARY KEY) COLUMNS;

If you want to track foreign key dependencies, enable foreign key supplemental logging:
```
ALTER DATABASE ADD SUPPLEMENTAL LOG DATA (FOREIGN KEY) COLUMNS;
```

For DBMS_FLASHBACK Package

To allow access to the features in the DBMS_FLASHBACK package, grant the EXECUTE privilege on DBMS_FLASHBACK.

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