What's a POS??

Mike McDonald mikemac@titian.engr.sgi.com
Fri, 09 May 1997 00:19:36 -0700

>To: lispos@math.gatech.edu
>Subject: Re: What's a POS?? 
>Date: Thu, 08 May 1997 23:16:27 -0700
>From: Kelly Murray <kem@franz.com>
>There are many approaches to persistent objects that give very different
>answers to questions on how it works.  

  That's precisely my point! People in this discussion are attributing
qualities to POSes that come from many different approaches. Some of
these qualities are mutually exclusive of each other. I'm trying to
get people to specify which of these many different approaches they
are advocating.

>The way to learn how they work is to go read the research literature,
>read the OODB companies product descriptions and white papers.

  Actually, I have some small knowledge about these things. I put
myself thru grad school implementing large database systems and I've
written an OODB for lisp for use in VLSI CAD design. I'm just trying
to get people to define their uses of the terms.

>I can point to AllegroStore as an existing, working
>commercial product which is an instance of a persistent CLOS that
>represents certain properties and implementation decision.
>There are many others too.
>My own persistent CLOS implementation is still in progress so some
>design decisions have not yet been made.
>It is a very different implementation than AllegroStore,
>but will likely have a similiar kind of API as AllegroStore
>which was actually mostly copied from Symbolics' Statice
>(customers wanted this same API)

  OK. Now I know what YOU mean when you talk about persistent objects
and persistent object stores. And that's different from what some
other people mean when they use the same terms.

>It is probably most useful to look and play with real working examples
>that use persistent CLOS.
>I hope to demonstrate how this all works with SMTP/mailer code that I'm
>working on.

  I'm looking forward to getting to play with it.

  Mike McDonald