A major reason we decided to store page sequencing in a METS structMap in the object rather than in RELS-EXT is a simple logistical one: we intend to deliver book objects to a viewer as single METS objects, so the viewer (and the METS disseminator) can build the book's structure all at once, rather than querying Fedora a bunch of times to get the sequence and structure on the fly. However, a viewer that was more tightly tied to Fedora repository would certainly benefit from being able to query the RI for sequence information.
Peter C. Gorman Head, University of Wisconsin Digital Collections Center pgor...@library.wisc.edu (608) 265-5291 On Aug 31, 2011, at 2:18 PM, aj...@virginia.edu wrote: > I agree with Scott's point that "page sequences can be considered a property > of containers ... rather than a property inherent in the page object itself", > and because of a well-known updating difficulty in the RI, it is not possible > to use RDF containers in RELS-*. See: > > https://jira.duraspace.org/browse/FCREPO-656 > > There is, however, a fair way to use the RI to this end-- you can construct a > linked list, or a doubly-linked list amongst the pages. That's what we do (a > doubly-linked list). We're therefore relying on the RI to be fast, which it > is (it is, after all, an _index_-- the repository is the data store). > Updating is fairly easy (create object with two relationships, then alter > four relationships of the preceding and following pages). We have no trouble > querying into the RI for results fast enough for a page-turner presentation. > > But then, we are strongly committed to RDF for as much structural metadata as > we can cram into it. {grin} > > --- > A. Soroka > Online Library Environment > the University of Virginia Library > > > > > On Aug 31, 2011, at 2:11 PM, Scott Prater wrote: > >> Hello, Joszef -- >> >> I'll send you a couple of sample objects in a separate email. >> >>> Not to mention, that I don't really have a clear vision, how to store page >>> orders in RELS... :) >> >> Nor do we. You could store the sequence triple in the object itself, >> something along the lines of <myobject> <hasPageSequence> "1", but then >> you'd have to query every single object to build a list of pages (not a >> real big deal in the resource index, but still, a little clunky). And >> what if you forget to scan a page, and your numbering gets all whacked, >> and you have to go back and add a page later (something that occurs more >> often than we would like to admit)? You'll need to update the page >> sequence triple in every following page object. >> >> An even more subtle problem crops up if your object has one page number >> in one context (say, a plate in a book) and another page number in >> another context (say, the same plate in an art exhibit catalogue): if >> you were to create these two relations in the page object, how would you >> express in a triple that I'm page 1 of book A, and page 3 of book B? >> This is a use case which demonstrates that page sequences can be >> considered a property of containers ("I'm a book, and I have this >> content at position X"), rather than a property inherent in the page >> object itself. >> >> That would be okay, except that there's no way to express in a book >> object's RELS-EXT triple that book object A contains page object A1 with >> the attribute page sequence "1". You can do that in METS, though. >> >> -- Scott >> >> >> -- >> Scott Prater >> Library, Instructional, and Research Applications (LIRA) >> Division of Information Technology (DoIT) >> University of Wisconsin - Madison >> pra...@wisc.edu >> >> ------------------------------------------------------------------------------ >> Special Offer -- Download ArcSight Logger for FREE! >> Finally, a world-class log management solution at an even better >> price-free! And you'll get a free "Love Thy Logs" t-shirt when you >> download Logger. Secure your free ArcSight Logger TODAY! >> http://p.sf.net/sfu/arcsisghtdev2dev >> _______________________________________________ >> Fedora-commons-users mailing list >> Fedora-commons-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/fedora-commons-users > > > ------------------------------------------------------------------------------ > Special Offer -- Download ArcSight Logger for FREE! > Finally, a world-class log management solution at an even better > price-free! And you'll get a free "Love Thy Logs" t-shirt when you > download Logger. Secure your free ArcSight Logger TODAY! > http://p.sf.net/sfu/arcsisghtdev2dev > _______________________________________________ > Fedora-commons-users mailing list > Fedora-commons-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/fedora-commons-users ------------------------------------------------------------------------------ Special Offer -- Download ArcSight Logger for FREE! Finally, a world-class log management solution at an even better price-free! And you'll get a free "Love Thy Logs" t-shirt when you download Logger. Secure your free ArcSight Logger TODAY! http://p.sf.net/sfu/arcsisghtdev2dev _______________________________________________ Fedora-commons-users mailing list Fedora-commons-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/fedora-commons-users
