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On 7/20/05, Ronald Bourret <rpbourret@r...> wrote: > Peter Hunsberger wrote: > > On 7/19/05, Ronald Bourret <rpbourret@r...> wrote: > > > >>Will the addition of XML data types to relational databases help this > >>problem, at least for data-centric schemas? It's a bit of an force-fit, > >>but it seems that mixed content could be mapped to and accessed from an > >>XML column when the meaning of that content is a single word, even an > >>annotated one. > > > > If you're indexing in any way (walking a Blob or shredding) then you > > need some form of schema support... > > Actually, virtually all native XML databases can index arbitrary XML. In > some cases, this is inherent in the internal structure of the database. > For example, NeoCore stores data in hash tables of the paths to that > data. Thus, the index and the data storage are the same. In other cases, > databases create more conventional indexes (such as B-trees) as > necessary, rather than simply in response to a create index command. > Whether this is always done or the user has the choice to limit what is > indexed depends on the database. > I didn't phrase that very well; what I meant was that in order to know what element you're putting where in the database you need to have some form of schema support. Eg, you need to know that X and Y are base elements and Z is an annotation that can be contained in or attached to either. I agree that the physical index itself is business as usual... <snip/> -- Peter Hunsberger
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