[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: XQuery types was Re: Yet another plea for XUpdat
At 10:12 AM 5/4/2002 -0700, Dare Obasanjo wrote: >The bottom line is that any XML database product that >supports XQuery and W3C XML schema plus an update >capability will have to support post-update validation >because the XQuery and W3C XML Schema "type" systems >leave the door open for too many things to be dynamic. > > >By the way here are some quotes from the Formal >Semantics document which point out what I mean by >validation vs. type system [ !!! SNIP !!!] >Especially with regards to restriction facets, there >simply is no way for this to be implemented without >something akin to post-update validation. Identity >constraints as well. In fact, when I think about even >making sure that the results of an update do not >result in an invalid content model for an element in >the document is pretty much another validation issue >not a type one. Static analysis is not an all-or-nothing thing. Relational databases do not use static analysis for constraints on values, but static analysis is important for relational databases. Restriction facets are generally constraints on values. Jonathan
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