James Trudeau wrote:
>Any conjecture/knowledge on why HP put the Jumbo's in the POSIX
> namespace instead of MPE/iX?  Seems to me that when they
> implemented in 5.0 it was supposed to be optional.  There was
> a discussion somewhere (on the list?) during the 4.5 era regarding
> putting in a "switch" to turn it off.  That got shutdown for technical
> reasons which I do not recall.  Anyhow, so howcome I got parta
> my data herd in my barn and part in my neighbor's barn?

James, the primary reason for using the POSIX namespace is the file names.
 In MPE, as you know, one can only have 8 characters, and with IMAGE the
last 2 are reserved.  So a database name with 6 characters has one file
(the root file) with a 6 character name that matches the DB name, and then
one file for each dataset with the last 2 characters matching the dataset
number.  Additionally, there will be other files depending on whether you
use Image/SQL, Superdex or Omnidex, and of course there are control files
(the GB file, for example) that should only exist when the database is
opened.

In any case, the bottom line is that most of the possible combinations
(36*36) for the last 2 characters are reserved.  This makes it real
difficult to decide how you chose file names for the additional jumbo
files.  Using the POSIX namespace allows the names to be "database##.###"
where the "##" is the dataset number (just like of old) and the ".###" is
the jumbo file number.  The MPE namespace file "database##" is a control
file which includes information such as how many ".###" files you should
have.  The first file that contains data would be in the POSIX namespace as
"database##.001", the second as "database##.002" and so on.

This was debated my many :), because of the issue you bring it.  It forces
jumbo set users to *have* to use the POSIX namespace.  However, in the end,
I believe the choice was made because it was the best of the known options
at the time (I'm not implying that there is another known option today,
just that there could be one in the future).

Hope this helps.

LB