- From: Ivan Mikhailov <imikhailov@openlinksw.com>
- Date: Fri, 02 Jul 2010 11:50:32 +0700
- To: Yves Raimond <yves.raimond@gmail.com>
- Cc: Kingsley Idehen <kidehen@openlinksw.com>, Henry Story <henry.story@gmail.com>, nathan@webr3.org, Pat Hayes <phayes@ihmc.us>, Toby Inkster <tai@g5n.co.uk>, Dan Brickley <danbri@danbri.org>, Linked Data community <public-lod@w3.org>, Semantic Web <semantic-web@w3.org>
Hello Yves, > > It's a virtuoso function surfaced as a predicate. > > "magic predicate" was an initial moniker used at creation time. > > "bif:contains" doesn't exist in pure triple form etc.. > > Why couldn't it? For example, you may want to express exactly what > triple lead you to give a particular result, and within that scope you > may end up having to write: "Brickley" bif:contains "ckley" in RDF. > > Forbidding literals as subjects makes this statement impossible to > express, however that's a very sensible thing you may want to express. > > There are also lots of literal search examples that comes to mind: > > "Acton" str:double_metaphone "AKTN" . > "Smith" str:soundex "S530" . Yes, SPARQL permits literals in subject position, and we use that for dirty hacks. That does not mean that raw data should permit the same. SPARQL (and especially our SPARQL/BI) uses many different things in subject position, e.g., variables (and expressions, up to subqueries) that's not an excuse to allow the same in raw data. I don't even say about technical price of the extension for both developers (extra work) and each user of any big RDF storage (extra hardware). I simply don't see a reason, because literals are simply _not_enough_unique_ to interlink data. [ ] str:double_metaphone_word "Acton" ; str:double_metaphone "AKTN" . and [ ] str:soundex_word "Smith" ; str:soundex "S530" . are at least protected from collisions and allow more properties to be added in a safe way. Best Regards, Ivan Mikhailov OpenLink Software http://virtuoso.openlinksw.com
Received on Friday, 2 July 2010 04:52:46 UTC