RE: Type checking in DASL

I have been assuming (or hoping, perhaps) that we will define just one
simple grammar that need not be all-powerful, but enough to support many
needs in the Web environment.  Since DASL can transport queries expressed
in any grammar, those who want something more complex and powerful can
define such grammars.

I think there will be a much greater variety of clients in the Web
environment than we are used to seeing in the DMS world.  For many of them
search will not be their primary value, but an added convenience.  Many of
them will want to be very simple, and will not be willing to invest much in
the search capability.  Some will be commercial products, others will not.

On the specific issue of whether we need type-specific operators, I still
cannot see it.  If a client doesn't want to do type-checking or conversion,
it should not have to.  If it chooses not to perform any edits before
submitting a query, it can have that policy.  It can rely on the server to
do those things.  It's the server that performs the comparisons and
collations, not the client.

I agree that it is important for us to be compatible with DMA, to the
extent that gateways can be constructed between the two.  But a simpler
subset of DMA's functionality in DASL would be sufficient for that. In
general WebDAV has positioned itself as a simpler subset of DMA
functionality, and DASL can continue that tradition.   

Other standards like SQL have taken the simpler path on comparison
operators, so I don't think we have to take DMA to be gospel here.

--Judy



Name:		Judith A. Slein
E-Mail:		slein@wrc.xerox.com
Phone:  	(716) 422-5169
Fax:		(716) 422-2938

Xerox Corporation
Mail Stop 105-50C
800 Phillips Road
Webster, NY 14580

Received on Wednesday, 6 May 1998 11:16:37 UTC