 |
|
Oracle
Automatic Auxiliary Instance Creation
Oracle Tips by Burleson Consulting |
This
is an excerpt from "Oracle 10g New Features for Administrators" by
Ahmed Baraka.
When you perform a tablespace point-in-time recovery
(TSPITR) to recover from certain database errors, Oracle Database
10g will now automatically create the auxiliary instance and remove
it after the recovery is over.
This automatically generated instance will be in the
same database server. Remember, as with previous versions, instance
creation introduces performance overhead during the recovery
operation.
Automatic creation of Temporary Datafiles
Starting from release 2, Temporary datafiles that
belong to locally managed temporary tablespaces are automatically
re-created during RMAN recovery operation. This eliminates the need
to manually create temporary tablespaces after recovery.
New RMAN Dynamic Performance Views
In Oracle 10.2 and above, in order to provide more
details about its operation, RMAN is supported by a number of new
dynamic performance views including:
V$BACKUP_ARCHIVELOG_DETAILS
V$BACKUP_ARCHIVELOG_SUMMARY
V$BACKUP_CONTROLFILE_DETAILS
V$BACKUP_CONTROLFILE_SUMMARY
V$BACKUP_COPY_DETAILS
V$BACKUP_COPY_SUMMARY
V$BACKUP_DATAFILE_DETAILS
V$BACKUP_DATAFILES_SUMMARY
V$BACKUP_JOB_DETAILS
V$BACKUP_PIECE_DETAILS
V$BACKUP_SET_DETAILS
V$BACKUP_SET_SUMMARY
V$BACKUP_SPFILE_DETAILS
V$BACKUP_SPFILE_SUMMARY
One other useful view is V$RMAN_BACKUP_JOB_DETAILS.
It informs you about history of all backups done by the RMAN. You
will find details like how long the backup took, how many RMAN jobs
have been issued, the status of each job, what time they started and
completed, rate of the backup produced and how fast data was read
and written by the process.
COL STATUS FORMAT
A9
COL HRS FORMAT 999.99
SELECT
SESSION_KEY, INPUT_TYPE, STATUS,
TO_CHAR(START_TIME,'DD/MM/YY HH24:MI')
START_TIME,
TO_CHAR(END_TIME,'DD/MM/YY HH24:MI')
END_TIME,
ELAPSED_SECONDS/3600 HRS
FROM V$RMAN_BACKUP_JOB_DETAILS
ORDER BY SESSION_KEY
COL INS FORMAT A10
COL OUTS FORMAT A10
SELECT SESSION_KEY,
OPTIMIZED,
COMPRESSION_RATIO,
INPUT_BYTES_PER_SEC_DISPLAY INS,
OUTPUT_BYTES_PER_SEC_DISPLAY OUTS,
TIME_TAKEN_DISPLAY
FROM V$RMAN_BACKUP_JOB_DETAILS
ORDER BY SESSION_KEY
Another new view is V$RMAN_BACKUP_TYPE. It informs
the type of backups performed by RMAN : BACKUPSET, SPFILE,
CONTROLFILE, ARCHIVELOG, DATAFILE INCR, DATAFILE FULL, DB INCR,
RECVR AREA and DB FULL.
The view V$RMAN_OUTPUT records the output (log) from
the RMAN jobs so that you can view it later. This view is useful for
checking log of scripted RMAN jobs as well as ad-hoc jobs.
Note: All those view are in-memory and cleared
upon the instance shut down.
Oracle Secure Backup
• In Oracle Database 10g Release 2, a new tool
called Oracle Secure Backup (OSB) is available. OSB enables you to
use RMAN to backup directly to tape library without using the costly
third-party MML layer.
• OSB can be controlled and administered via Oracle
Enterprise Manager or obtool command-line.
• Beside backing up the database, OSB can be used to
backup filesystems as well.
 |
If you like Oracle tuning, see the
book "Oracle
Tuning: The Definitive Reference", with 950 pages of tuning
tips and scripts.
You can buy it direct from the publisher for 30%-off and get
instant access to the code depot of Oracle tuning scripts. |
