Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!mnetor!uunet!husc6!sri-unix!quintus!pds
From: pds@quintus.UUCP (Peter Schachte)
Newsgroups: comp.sys.amiga
Subject: Re: Version Numbers (Re: The Next Generation)
Message-ID: <296@cresswell.quintus.UUCP>
Date: Mon, 30-Nov-87 17:19:05 EST
Article-I.D.: cresswel.296
Posted: Mon Nov 30 17:19:05 1987
Date-Received: Thu, 3-Dec-87 06:08:46 EST
References: <5294@ccicpg.UUCP> <2803@cbmvax.UUCP> <516@mcdsun.UUCP> <1604@bsu-cs.UUCP>
Organization: Quintus Computer Systems, Mountain View, CA
Lines: 17
Summary: Compress old versions


Version numbers can be VERY useful.  They have saved me a lot of time
on several occasions.  But they DO take up a lot of space.  So why not
do the sort of thing SCCS does:  store previous versions as a set of
differences from the following versions.  Thus getting back (or looking
at) old versions (which you wouldn't do very often) would be pretty slow,
but the disk space cost would be drastically reduced.  SCCS uses
line-by-line diffs, which isn't very good, but you could easily use a
byte-by-byte diff scheme, which would be more general, and sometimes
smaller.  The code to compute the differences and reconstruct old
versions from newer ones plus a set of diffs could be incorporated into
the kickstart or workbench.

Remember, multiple versions are good for more than backup, they also
let you ask questions like:  what have I done to this file lately?
-- 
-Peter