Sybase 12.4.2 - Manual (Page 417)

CHAPTER 11 Backup and Data Recovery
397
• For a full restore, the Catalog Store (by default the .db file) and the
transaction log (by default the .log file) must not exist in the location you
are restoring to. If either of these files exists, you must delete it or move it
to a different directory before doing the full restore.
When a full restore begins, it destroys all old database files and then
recreates them. The requirement that you manually delete the Catalog
Store and transaction log files protects you from doing a full restore
accidentally.
• For any incremental restore, the Catalog Store (.db) and transaction log
(.log) files must exist. If they exist, but in a different location than the one
you are restoring to, you must follow the procedure described in “Moving
database files”. If either of these files does not exist, you can only do a full
restore.
• For any incremental restore, the database must not have changed since the
last restore.
Restore requires exclusive access to the database. The default database server
startup option
-gd DBA guarantees that only the DBA can start a database. To
ensure exclusive access, start the database server with the -gd DBA option set,
but do not start the database you are restoring. RESTORE automatically starts
the database in such a way that no other users can connect to it.
You must restore an entire backup or set of backups. Restoring individual files
is not supported. However, you can move database files to a new location,
using the
RENAME clause of the RESTORE command.
Restore accommodates dbspace changes
During a set of incremental restores, RESTORE creates and drops dbspaces as
needed to match what was done during the period of operation encompassed
by the restores. For example, assume that you make a full backup of a database,
then add a dbspace to that database, and then do an incremental backup after
adding the dbspace. When you restore from these backups,
RESTORE creates
a file for the new dbspace, at the start of the incremental restore. Similarly, if
you drop a dbspace, it is dropped during the restore, although the actual file is
not removed.