If you are running the database in ARCHIVELOG mode (strongly recommended!), you can
use the offline backups as the basis for a media recovery, but an online backup would typically
be easier to use for recovery in that situation.
Of the two remaining methods, which one is more appropriate? For production environments,
the answer is almost always online backups. Online backups, with the database running in
ARCHIVELOG mode, allow you to recover the database to the point in time immediately
preceding a system fault or a user error. Using a Data Pump Export-based strategy would limit
you to only being able to go back to the data as it existed the last time the data was exported.
Consider the size of the database and what objects you will likely be recovering. Given a
standard recovery scenario, such as the loss of a disk, how long will it take for the data to be
recovered? If a file is lost, the quickest way to recover it is usually via a physical backup, which
again favors online backups over exports.
If the database is small, transaction volume is very low, and availability is not a concern, then
offline backups may serve your needs. If you are only concerned about one or two tables, you
could use Data Pump Export to selectively back them up. However, if the database is large, the
recovery time needed for Data Pump Export/Import may be prohibitive. For large, low-transaction
environments, offline backups may be appropriate.
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