I have used DDX with details for some time, and the problems that appeared
early on have long since been corrected.  I think for most environments,
there is no reason not to use it.  There are some applications, notably
Amisys, that will make a decision about whether to continue with a process
based on the capacity of a target datset, which fail to detect that DDX is
implemented, thus reducing its usefulness.  If you don't have that problem,
go for it.

With respect to MDX, I am not aware of any bugs.  Be aware that any entries
that end up in the "expansion" part of a master are secondaries, so you are
seeing diminished performance by the time MDX coms into play.  It is a good
way to prevent surprise capacity problems, but should not be relied upon to
manage your master capacities.  Any rule of thumb concerning master
capacities, such as keeping them below 80% full, should be applied to only
the initial capacity, i.e. stay below 80% of the initial capcity, not the
maximum.

-----Original Message-----
From: Gibson Nichols [mailto:[log in to unmask]]
Sent: Wednesday, February 14, 2001 8:02 AM
To: [log in to unmask]
Subject: Is dynamic dataset expansion good?


When some of the features of dynamic dataset expansion first came out (may
have been the master dataset and perhaps some combination with other
features like jumbos) there were problems.  Are there still problems? Should
I avoid dynamic dataset expansion?

Just upgraded our Orbit backup software so we can use the option which
allows us to keep the system up during the entire backup.  Ran into some
messages when the database logging was turned off during the backup.  The
Orbit folks told us that it is best to keep logging turned on.  Okay, but we
need to increase the capacity sometimes . . . so thus my need to use dynamic
dataset expansion.