Re: faces performance issues & database lookup

Philippe-Andre Prindeville (philipp@inf.enst.fr)
Mon, 8 Apr 91 14:21:54 +0200

> Date: Thu, 4 Apr 91 14:28:46 +1000
> From: John Mackin <john@syd.dit.csiro.au>
> To: The Faces List <faces@Aus.Sun.COM>
> Subject: faces performance issues & database lookup

> Hey! Here it comes man!

> } If so, have these alternatives been considered?
> } - a dbm database of face locations that can be searched faster than
> } the directory structures; or even loaded and kept in core by the
> } faces program for very fast searches; something would have to update
> } the database every once in a while

> This is one of the ideas I really like. Here are some of my thoughts:
> [...]
> Dbm format would probably work. I seem to remember that DBM(3X) had some
> stupid upper limit of 1000 records or something. I'm sure that can be
> worked around; there are probably better database manipulation packages
> anyway. I believe Henry Spencer and Jeff Collier put one together for C
> news.

> I don't mind this idea, but... dbm will NOT work, and ndbm will NOT work,
> and we have to remember that not all UNIX variants have dbm at all. Both
> dbm and ndbm share Rich's ``stupid upper limit'', and it's very bad. The
> relevant manual entry quote is this:

> [ ... ]

> The thing about this, though, is that it isn't conceptually clean.
> _Appearing_ to use the directory structure of the filesystem to
> represent the database is beautiful. _Actually_ doing so is a
> performance disaster, as we have found out.

Hmmm. You're overlooking one possibility: using X.500. There is
the server that comes in the ISODE package from M.T. Rose, et al.
Such a database would be an ideal place to put the data... Otherwise,
people with YP (ahem, NIS) can use that (sigh).

-Philip