- From: Bijan Parsia <bparsia@cs.man.ac.uk>
- Date: Mon, 5 Mar 2007 08:58:24 +0000
- To: Lee Feigenbaum <feigenbl@us.ibm.com>
- Cc: RDF Data Access Working Group <public-rdf-dawg@w3.org>
In SQL, SELECT has two parameters, ALL and DISTINCT with ALL being implicit. One way to handle the sort of variability in result set desired here is to make ALL *not* be implicit, but have the bare SELECT mean something like "something between ALL and DISTINCT depending on the implementation". SQL defaults to ALL because, I think, of the strong perception that it is "always" cheaper (which in fact depends on the relative cost of pruning dups and transmitting them). Making the default "whatever the implementation thinks is cheapest" seems in the spirit of this and ALL allows access to the max sane result set (plus, implementations can chose not to support it...it can be tricky in OWL since you'd have to get all derivations...not impossible but non-trivial). Cheers, Bijan.
Received on Monday, 5 March 2007 08:58:43 UTC