=> On Fri, 16 May 2003 10:31:10 -0400, Bill Boyer <bill.boyer AT VERIZON DOT 
NET> said:


> For syncronizing the history with it that would depend on your retention of
> the bakcups with the DB2ADUTL utility. Set the database attributes: (DB2 GET
> DB CFG FOR <database>)

>  Number of database backups to retain   (NUM_DB_BACKUPS) = 30
>  Recovery history retention (days)     (REC_HIS_RETENTN) = 60

I'm somewhat aggravated that the redbook doesn't include even a single mention
of these arguments (or at least my PDF search didn't find them)

I am encouraged (or discouraged) to learn that there is confusion on the DB/2
lists about this, too.


> According to one of the DB2 manuals I read through, after the completion of
> a full backup DB2 will automatically prune the history file based on these
> parameters.

I think that this is pruning the -db2- history file, and that it does not
address any expiration/deletion on the TSM server.

To translate into files-on-disk terms:

If NUM_DB_BACKUPS is 4 and REC_HIS_RETENTN is 30,

then after completing the sixth full backup there are two database backups
still sitting around on disk, but DB/2 doesn't know that they are there any
more.  If you were to say

restore database foobar from /place/where/old/backup/lives/

it would just work, but that backup isn't recorded in DB/2's internal recovery
data.

Ditto for the logs and fulls that were taken 45 days ago; they are not somehow
magically deleted from the disk, but they are no longer present as far as DB/2
is concerned.


- Allen S. Rout