Craig Fairchild popped up from the MPE/iX Large Files
"skunk works" and said:

> Image has not yet adopted large file capability to extend the
> size of Image databases. Through the use of jumbo datasets
> Image already has the capability to grow database sizes
> beyond the 4GB boundary. At some point in the future the
> Image team may make use of large files as the underlying
> technology behind their large databases, but this is not the
> case in release 6.5.

I'm going to go out on a limb here, and correct one word that
Craig used in his above:   He said ".... the Image team MAY
make use of large files.... ".  From the current "Now / Soon
Available in Image/SQL" list (added for the 2000 SIGIMAGE
Ballot), item # 48:
==========================================

Use MPE "large files"  to get > 80 GBytes in one dataset,
instead of increasing the number of JUMBO "chunk files".
SOON
==========================================

....  so unless I totally mis-read one or more of the slides the
CSY R&D Database Lab showed at the last SIGIMAGE meeting,
what Craig *meant* to say was something like:    ".... the Image
team WILL make use of large files as the underlying technology
behind their large databases sometime soon, .... ".       ;-)

....  either that, or I've got a mistake on the "Now / Soon" list.
I don't add items unless and until HP is able to say with some
reasonable level of confidence they are going to do them.  That
doesn't meant every item listed as "SOON" on that list is bet-the-
ranch guaranteed to happen (a few have become moot or OBE
after first appearing on "Now / Soon");  just that odds are good
"SOON" will turn into "NOW" eventually....


Jerry and Craig both noted the immediate benefit of Large Files
to IMAGE users:

> However, the good news is if you have a JUMBO master set
> which contains more than 3.75GB of key data, you can now
> successfully attach a b-tree index to that master set.

I believe a number of large sites were at or close to this limit, so
getting Large Files for the NM-KSAM IMAGE B-Tree files was
certainly timely for those sites...

> Furthermore, you can fully extract a JUMBO set to a large file
> and sort it either using utilities such as SUPRTOOL ......


Correct....   But one thing worth noting:  Since sorting records is
essentially an exponential of the number of records involved, if
you try and sort 70GB of data from an IMAGE Detail in a large
MPE flat file you might be able to go out and have dinner while
you are waiting for it to finish....   several times....

Ken Sletten
SIGIMAGE Chair