RE: Compression vs compaction for SAV

["Shaw, David" <dshaw@xxxxxxxxxxx>]

Patrick,

The zip algorithm is quite different from the /400's save compression
algorithm, so this is expected.  Try putting a zip file from a PC in the IfS
and then doing a SAV to a save file with DTACPR(*YES) - there should be
significant compression in that scenario, too.  It's only when the
algorithms are very similar, such as zip compression and asynch modem
compression, that there's no gain expected from the second compression step.

Dave Shaw
Spartan International, Inc.
Spartanburg, SC

> -----Original Message-----
> From: Patrick Townsend [mailto:townsend@patownsend.com]
> 
> Don,
> 
> I find it interesting, too. Our zip compression algorithm 
> regularly gets 
> about 60 percent compression on a save file that is *already* 
> compressed.
> 
> Patrick
> 
> At 11:51 AM 5/24/2000 -0400, Don wrote:
> 
> 
> >Dumb question du jour:
> >
> >Out of curiosity, if you use compressions on the 400 you get 
> about a 1.7:1
> >ration, but if you use compaction you get a 3:1 ratio.
> >
> >Now, this begs the question, why doesn't IBM improve the compression
> >algorithm used to in effect be the compaction algorithm as 
> we get alot
> >better media utilization...?
> >
> >What am I not seeing here???
> >
> >Don in DC
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