Because
read-only tablespaces are not being written to, there are special
considerations to take into account, which can make the recovery process faster
and more efficient. You do not have to put a read-only tablespace into backup
mode or take it offline before copying it to the backup location. Simply copy
it.
When
restoring a read-only tablespace, take the tablespace offline, restore the data
files belonging to the tablespace, and then bring the tablespace back online.
Consider
the following scenario, where a read-only tablespace is changed to be
read/write:
1. Make a backup of a read-only tablespace.
2. Make the tablespace read-write.
3. Recover the tablespace.
The backup
you made in step 1 can still be used to recover this tablespace, even though,
since the backup was made, the tablespace was made read-write, and has even
possibly been written to. In this case, the tablespace requires recovery, after
the files are stored from such a backup.
