Backing Up The Database - Red Hat NETWORK SATELLITE 5.3.0 Installation Manual

Chapter 8. Maintenance
Option
start
shrink-segments
status
stop
tablesizes
verify DIRNAME
Table 8.1. RHN DB Control Options
Note
Database statistics are collections of data that describe more details about the database
and the objects in the database. These statistics are used by the query optimizer to
choose the best execution plan for each SQL statement. Because the objects in a
database can be constantly changing, statistics must be regularly updated so that they
accurately describe these database objects. Statistics are maintained automatically by
Oracle. However, if your database has performance issues after a significant amount of
data changes, consider performing manual gathering of statistics.
Note
After deleting large amount of data, use the segment-shrink feature to reclaim
fragmented free space in an Oracle Database segment. The benefits of segment-
shrink are compaction of data that leads to better cache utilization and the compacted
data requires fewer blocks to be scanned in full table scans, which both lead to better
performance.
The segment shrink feature works only on newly created Oracle Database 10g Release
2 that comes with RHN Satellite Server 5.2.0. Due to different default database settings
in Oracle Database 9i this feature does not work on databases that were upgraded from
previous RHN Satellite Server releases.

8.4.2. Backing up the Database

Red Hat recommends performing nightly backups of the Embedded Database and moving the
resulting directory to another system via NFS, SCP, FTP, etc. Preferably, this backup system resides
off-site. To conduct a backup, shut down the database and related services first by issuing the
following command as root:
60
Description
Starts the database instance. This can also be
accomplished by issuing the service rhn-
database start command as root.
Shrinks RHN Oracle database segments with signifcant
amounts of free space.
Shows the current status of the database, either
"running" or "offline".
Stops the database instance. This can also be
accomplished by issuing the service rhn-
database stop command as root.
Show space report for each table
Verifies the contents of the backup kept in DIRNAME.
This command checks the md5sums of each of the
files kept in the backup.