ALLBASE/SQL also provides the capability to restore all the files in the
DBEnvironment (full recovery) or to restore only a subset of the files
in the DBEnvironment (partial recovery).
You may choose full or partial recovery when using either
nonarchive or archive mode logging.
If a crash occurs in a DBEnvironment that is contained solely on one drive,
you must do a full recovery of the entire DBE (or that portion of the
DBEnvironment that you stored because it was essential data).
If a crash occurs to a DBE that is spread across several drives,
regardless of whether you are using nonarchive or archive logging,
the kind of recovery you must do depends on certain operating system
conditions and on which ALLBASE/SQL files were destroyed in the crash.
The failure conditions on the operating system must be such that you are
able to restore only those files that were located on the device that
failed.
Your failure
conditions may require you to restore files on several or all drives
associated with your DBEnvironment. If you must restore files on several or
all devices, partial recovery is not useful. See your system administrator
for details for your operating system. Be sure that your
disaster recovery plan includes the operating system considerations needed
for recovery of your DBEnvironment, not just the ALLBASE/SQL considerations.
You must do a full recovery if any of the following files were destroyed in
the crash:
Any of the SYSTEM DBEFiles (DBEFile0 or any files you added to the SYSTEM
DBEFileSet) and/or the DBEConFile which is stored on the same drive as the
SYSTEM DBEFiles.
In the case of single logging, your single log file; unless, in the case of
archive logging, the file has never been used, or
you have already stored the log file off, and the file has
not yet been reused.
(If you are using dual logging, the loss of one leg of the log does not
require you to restore the DBEnvironment. Just repair the damaged device and
create a new set of log files to restore dual logging.)
If the crash destroyed any other files than those listed above, you can
repair the damaged drive and then do a partial recovery which only includes
the files that were damaged in the crash.
While the damaged drive is out of operation, you can still operate the remainder
of the DBEnvironment so long as the operating system permits and
so long as users only access the DBEFiles on the
undamaged drives. Any attempt to access files on the damaged drives will
result in the generation of an error message.
