SCCS vs RCS

[Doug Gwyn]

In article <356 at wjh12.harvard.edu> gst at wjh12.UUCP (Gary S. Trujillo) writes:
>The article seems to make a good case for the superior efficiency and
>performance of RCS, which seems due largely to the fact that most checkouts
>are of most-recent versions, which RCS can do quickly since it uses the
>scheme of storing the most recent version of files (incorporating embedded
>control information), and applies reverse deltas if older versions are
>requested.

Some time ago, I measured the relative speeds for checking out versions
of text files maintained by both SCCS and RCS.  Checking out the most
recent version was so fast for both systems that arguments based on
relative "efficiency" are suspect.  For checking out an arbitrary version,
SCCS was considerably faster that RCS, taking approximately the same time
as for the most recent version.  Contrary to claims one often hears
repeated, SCCS does not maintain a base document plus separate "forward
deltas" which must be applied one after the other to arrive at a version;
it keeps the delta information mixed into the document so that a one-pass
extraction can be done.

There are probably more UNIX systems licensed for SCCS, which has been a
standard part of AT&T UNIX releases since System III (inclusive), than
come with RCS already installed.  Obtaining, installing, and maintaining
RCS is probably not a big deal in a research environment, but it might be
a factor for commercial use.

Certainly both revision control systems have their problems, but they
beat doing without.