Brian,

You are correct about the pointers, NOT correct on the logical delete
flag - there is a bit map that is marked logical delete, so that when
you do a serial read of the detail dataset, these entries that are
flagged deleted are not returned from the call.

Wyell

>>> Brian Donaldson <[log in to unmask]> Tuesday, November 28, 2006
11:40:31 PM >>>
I had to go and do some research on TurboIMAGE again just to refresh my
 
memory before
I go throwing in my 0.5 cents worth on this topic --
 
Image detail sets:
 
There is no such thing as a "logical delete" or "logical delete flag."

When a program calls DBDELETE on a *detail* dataset the BACKWARD and 
FORWARD 
entry pointers of the previous and next entry on the chain no  longer
point 
to the DBDELETE'd detail entry. The DBDELETE'd entry is no longer 
accessible. 
This DBDELETE'd entry then becomes part of the delete  chain.
 
If the detail dataset employs sort keys then the updating of the
backward  
and forward pointers gets even nastier. TurboIMAGE effectively "breaks"
the  
chain to rebuild the 
backward and forward entry pointers on the chain........
 
 
If you DBDELETE entries from a manual master dataset and said 
DBDELETE'd 
entry is part of a synonym chain then that entry is supplanted  with
the next 
entry on the synonym chain. For example, if there are 6  entries on a
synonym 
chain and you DBDELETE entry #3, then
entry #4 moves up to entry #3, entry #5 moves up to entry #4, entry #6 
moves 
up to entry #5.
 
 
Just my 0.5 cents worth of what I know of TurboIMAGE.
 
 
Brian Donaldson.

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *


IMPORTANT WARNING: The information in this message (and the documents attached to it, if any) is confidential and may be legally privileged. It is intended solely for the addressee. Access to this message by anyone else is unauthorized. If you are not the intended recipient, any disclosure, copying, distribution or any action taken, or omitted to be taken, in reliance on it is prohibited and may be unlawful. If you have received this message in error, please delete all electronic copies of this message (and the documents attached to it, if any), destroy any hard copies you may have created and notify me immediately by replying to this email. Thank you.

* To join/leave the list, search archives, change list settings, *
* etc., please visit http://raven.utc.edu/archives/hp3000-l.html *