a message dated 96-03-13 15:35:01 EST, [log in to unmask] (Gilles Schipper)
writes:
 
>I wrote, in response to Tom Stelter:
>
>>I believe that Image logging is NOT dependent on physical entry number -
and
>>that is precisely why I suggested your logging cycle should not require
>>resetting in the event of capacity changes - subject to the caveats I
>described.
>>
>>I'm sure others will correct me if I'm wrong.
>>
>I should emphasize that I believe Image logging is NOT dependant on physical
>entry number FOR CAPACITY CHANGES, for both masters and details - which is
>why I believe that logging cycle resetting is unnecessary FOR CAPACITY
>CHANGES.
>
>
 
The mists of time are parting a little.  I believe that DBRECOV uses the
address for detail entry work, and uses the key value (hashing and all that)
for masters.  This is why a logging cycle would be unaffected by a cap change
(expand only for details) but would be totally tumbled after a (detpack,
reorg) of a detail dataset. The key value is unique for master entries, and
the record number is unique for detail entries.
 
The log record layout in appendix E of the IMAGE manual shows the dataset
type being recorded as well as the record number.  In addition, for masters
only, the offset to the key value is recorded as well.  It also seems that
the key value is recorded also.
 
It is interesting to note that, if I am correct, DBRECOV has been using for
years, the key value for master dataset access and the record number for
detail dataset access.  If this is the case, why, oh why, can't we get HP to
see that it is the same thing which is needed to enable MS Access attachments
to detail dataset.  There is no problem with master sets as MS Access uses
the key value, but detail datasets would be accessible using the record
number, which is unique.  But I digress. . .
 
 
Kind regards,
 
Denys. . .