handling metadata with multiple values

[Gretchen Greene]

Hi Ray,

Wil addressed your first point.

As for using the ucdList element...i do not have a specific
implementation in mind although several fit the bill SAX, DOM,  and a
simple backend db would help for any sorting/indexing.  My understanding
would be in the contruction of a query engine,  ideally a web service
that could analyze and construct a query based on the 'available' data
ucds.  For example,  like in the galaxy morph demo when we wanted to
search for galaxy catalogs and then also redshift,  then to select on
range.  With ucd information you could agent on top of the registry (DOM
is good suggestion,  I'm not too familiar with the API dev though).  Web
service would not matter which DOM/SAX used.  For prototyping I would
simply go with the quicker dev strategy.


-gretchen

-----Original Message-----
From: Ray Plante [mailto:rplante at poplar.ncsa.uiuc.edu] 
Sent: Tuesday, August 12, 2003 2:34 PM
To: Gretchen Greene
Cc: registry at ivoa.net
Subject: RE: handling metadata with multiple values

Hi Gretchen,

Hmm, I thought you guys didn't like the list elements (or at least Wil 
didn't).

> I also endorse the ucdList element and hope to see this added into the
> VOResource schema.  This element would simplify mining metadata
content
> to find potential data sets which will satisfy data value driven
query.
> In other words a high level filtering capability.

Could you expand on this a little more about how it would help?  That
is, 
how do you envision extracting values to test against a query?  (e.g.
will 
you extract into a database first?  using an ots tool or something
custom 
written on top of, say, DOM & JDBC?)

There is no difference in the information stored in the two approaches.

So the differences are in how you access the data programmaticly and how

it looks.  (Any others?)  My discussion addressed the programmatic
issues.  
I don't want to discount the ascethetics, but I think it is important to

understand which kind of issue we're talking about.

cheers,
Ray