Database Reference
In-Depth Information
Configuring the Database for Backup
and Recovery
The ARCHIVELOG and NOARCHIVELOG modes of the database really boil down to what
your backup and recovery needs and requirements are. If your recovery needs are simple, and
you just want to restore to the point of your last backup, then you can leave your database
in NOARCHIVELOG mode and do offline backups. If your database uptime requirements
provide time to shut down the database for your backup, then NOARCHIVELOG mode will
work fine for you.
If you are going to do offline backups of your database in NOARCHIVELOG mode,
then you can pretty much ignore this section. All you will need to do there (as we will cover
in the next section) is determine the location of the files you need to back up and the loca-
tion to which you want to back them up, shut down the database, and back it up.
When you want to perform online backups, or if you want to be able to recover offline
backups beyond the time of the backup, then the database needs to be in ARCHIVELOG
mode. Putting the database in ARCHIVELOG mode requires some configuration, which
we will discuss first. Once you have configured the database, you will then actually put it
in ARCHIVELOG mode, which we will cover next.
You will need to understand both NOARCHIVELOG and ARCHIVELOG mode for
the OCP exam. While manual database backup and recovery-related questions will only
ask you about NOARCHIVELOG mode situations, RMAN questions may well ask you
about backup and recovery in both modes.
In the following sections, we will discuss configuring the database for ARCHIVELOG
mode operations (no additional configuration for NOARCHIVELOG mode operations is
required unless you want to configure the Fast Recovery Area for RMAN, which is covered
in Chapter 3), and then we will discuss actually putting the database in ARCHIVELOG
mode. Finally, we will discuss some database views that will be useful when managing a
database in ARCHIVELOG mode.
Configuring for ARCHIVELOG Mode
The first step to putting the database in ARCHIVELOG mode is to set the database param-
eters. You need to set the database parameters so that the ARCH process will work cor-
rectly when it needs to archive the online redo logs, creating archived redo logs.
You will want to consider setting several parameters when you are going to put the
database in ARCHIVELOG mode. A number of parameters are directly associated with
user-managed backup and recovery in ARCHIVELOG mode. Table 1.2 describes these
parameters.
Search WWH ::
Custom Search