At 04:42 PM 12/6/97 EST, Wirt Atmar wrote:
>However, the primary reason that I believe that
>b-trees should be the default condition is because a great number of HP3000s
>are not run as "large" systems, with a well-trained data processing staff on-
>site, but by ordinary business people.

Unfortunately I have to disagree with Wirt about defaulting b-trees on.

By having btrees (SSI) automatically on not only will cost additional
storage, but will also cost additional performance overhead which does
not add benefit when the application is unaware of the feature and
does not take advantage of it. It is quite possible that the additional
overhead costs will not be noticed, especially for smaller operations
which don't normally have performance concerns.

However, there is also the issue of awareness, in terms of changing
backup procedures/commands.  Also, what about shops that share
databases via a tape?  Will they know to be on the same release of
IMAGE or will they experience an IMAGE 'unknown version' error when
a SSI base is ported to an older version of MPE?

If indeed these customers are solely business people running a turn-key
application, chances are they are supported by some consultant or the
application vendor.  I believe it should be these folks who help the
customer prepare for and take advantage of SSI whcn appropriate.

A possible down-side might be those large shops who have the resources
but are now impacted to have something enabled which they do not want
or are ready to utilize.  IMAGE/DBUTIL would have to have another flag
that could be used to tell IMAGE upon a DBOPEN not to construct all
the SSI indexes on the master so these shops could disable the automatic
building of indexes upon a DBOPEN.  Otherwise, without SSI's being
automatically built with the DBOPEN, how else does it automatically get
setup for the small shops that don't have a staff?  If done via DBUTIL
and not DBOPEN, when creating a database, it does not affect existing
bases, hence does not meet the '100%, always there' approach.

I believe both Wirt and I agreeded/campaigned with HP to have CIUPDATE default
set to ALLOW.  But in this case I have to disagree with setting SSI to
on by default.  There is little/no benefit unless the user or application
is ready to take advantage of it. Even existing QUERY command files would
probably not benefit as they too, would have to be updated to use it and in
doing so, SSI could be manually enabled as needed.



/jf
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                         Friday, December 5th

            Today, in 1933 - The 21st Amendment took affect.
   Tomorrow (Sat), in 1790 - The U.S. Congress met for its first
                             session in Philadelphia.

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