QUESTION 41
You are using the control file to maintain information about the database backups that are being performed by
Recovery Manager (RMAN).
Identify two scenarios is which you must have a recovery catalog. (Choose two.)
A. To store the backup information of multiple database
B. To restrict the amount of space that is used by the backups
C. To maintain a backup for a certain time is set bythe CONTROL_FILE_RECORD_KEEP_TIME parameter.
D. To list the data files that were in a target database at a given time by using the AT option of REPORT
SCHEMA command.
Answer: AD
同620题：http://blog.csdn.net/rlhua/article/details/19166841
atClause
This subclause specifies a point in time as a time, SCN, or log sequence number. You must be connected to a recovery catalog when issuing a REPORT SCHEMAcommand with an AT clause.
| Syntax Element | Description |
|---|---|
AT SCN integer |
Specifies an SCN. |
AT SEQUENCE integer |
Specifies a log sequence number. The integer indicates the time when the specified log was first opened. |
THREAD integer |
Specifies a redo THREAD number. The integer indicates the time when the thread was first opened. |
AT TIME 'date_string' |
Specifies a date (see Example 3-14). The NLS_LANG and NLS_DATE_FORMAT environment
variables specify the format for the time. |
Explanation/Reference:
Section: Backup, Recovery & Recovery Manager (RMAN)
SYBEX 1Z0-053 Study Guide, Chapter 5: Using the RMAN Recovery Catalog
Identify situations that will require the RMAN recovery catalog.
Understand that the recovery catalog is largely optional. A recovery catalog will be needed for storing scripts
, and it will be required if you want to store backup records longer than one yearor beyond the setting of
CONTROL_FILE_RECORD_KEEP_TIME.
Oracle Press 1Z0-053 Exam Guide, Chapter 3: Creating and Maintaining an RMAN Catalog
Finally, using a recovery catalog permits you to use the following RMAN commands:
-BACKUP...KEEP UNTIL TIME Keep a backup for a period of time that differs from the configured
retention policy.
-BACKUP...KEEP FOREVER Keep a backup indefinitely or until you manually remove it.
-REPORT SCHEMA...AT Show the structure of the database at a specific time in the past.