Re: [Exist-development] Metadata in eXist

[José M. F. G. <jm...@us...>]

Hi everybody,
	we can have a look at the different approaches on filesystems world. In Mac OS X HFS+ and Windows NTFS there is the concept of forks, like several named streams of bytes attached to a file. One of those named streams is the default one, i.e. the file content. On UNIX you have the extended file attributes concept (http://en.wikipedia.org/wiki/Extended_file_attributes), and it is a key/value model.

	MarkLogic implementation is interesting and a good starting point, but I guess it does not allow attaching binary contents as metadata, which is a limitation. Some scenarios can be, for instance, a JPEG image stored in eXist could have some metadata in XML describing its EXIF properties, and binary metadata like a thumbnail, and SVG or XSL-FO documents could also have as binary metadata a thumbnail.

	Cheers,
		José María

On 28/07/10 17:55, Patrick Bosek wrote:
> I really like the concept of implementing metadata axis.
>
> After reading over MarkLogic's implementation, I think it may be a very good idea to essentially mimic them. It looks like their system would accomplish most of the goals expressed here thus far. And I'm always a proponent of consistency.
>
> Thoughts?
>
> Cheers,
>
> Patrick
>
> On Wed, Jul 28, 2010 at 9:50 AM, Joe Wicentowski <jo...@gm... <mailto:jo...@gm...>> wrote:
>
>     Very interesting discussion; I second all that Dan said about his use
>     cases.  Just a note on Adam's e-mail:
>
>      > The new user customisable metadata becomes a simple key value store
>      > and is indexed on document id and unique key name. Each value follows
>      > XQuery datatype rules and may be either an atomic value or a sequence.
>      >
>      > We then establish a metadata axis which is available in XQuery. From
>      > here we can use the standard predicates and update facilities of
>      > XQuery to maintain the metadata. The context of the metadata axis
>      > would always be the document root of the current node as metadata is
>      > on a per-document level, not a per-node level.
>
>     The metadata:: axis strikes me as similar in notion to the MarkLogic
>     property:: axis, although the latter stores metadata as an XML node
>     rather than key/value pair.  See:
>
>     http://docs.marklogic.com/4.1doc/docapp.xqy#display.xqy?fname=http://pubs/4.1doc/xml/dev_guide/properties.xml
>
>     I raise this as an existing implementation for comparison.
>
>     Joe
>
>
>
>
> --
> Patrick Bosek
> Jorsek Software
> Cell (585) 820 9634
> Office (585) 239 6060
> Jorsek.com
>
>
>
> ------------------------------------------------------------------------------
> The Palm PDK Hot Apps Program offers developers who use the
> Plug-In Development Kit to bring their C/C++ apps to Palm for a share
> of $1 Million in cash or HP Products. Visit us here for more details:
> http://p.sf.net/sfu/dev2dev-palm
>
>
>
> _______________________________________________
> Exist-development mailing list
> Exi...@li...
> https://lists.sourceforge.net/lists/listinfo/exist-development

-- 
"La violencia es el último recurso del incompetente"
	- Salvor Hardin en "La Fundación" de Isaac Asimov
"Premature optimization is the root of all evil." - Donald Knuth

José María Fernández González
e-mail: jos...@gm...