Current approaches

[Todd]

Hi all -

One of the first tasks of the HDMC-Registries group is to evaluate
current approaches and solutions in establishing a robust Registry. A
Registry is an essential component of a VxO. It allows the
registration and sharing metadata which describes resources in the
data environment. A Registry has two sides which can be considered a
front-end and a back-end. The front-end is an API which allows queries
to located registered metadata. The back-end imports metadata from a
management system. Currently the SMWG, VEPO, VHO, VMO, VSPO and VWO
use "git" to manage the metadata. Metadata is harvested from git
repositories to enable search and retrieval services of the VxOs. The
SMWG and VMO use the "SPASE Registry" service. The VMO and the VHO
also use SPASE-QL.

This leads to two questions:
1. Which metadata management solutions are others using?
2. Which access solutions are in use?

[Chimiak, Reine A. (GSFC-5870)]

The VSPO software uses the eXist database to access the displayed information. The data exchange is done thru XQuery/XPath requests. The eXist database is populated in part (SMWG metadata) by doing automatic pulling from the Git repository.

[Joe Hourcle]

The things I learned today:

* My spam filter doesn't like the terms 'VMO', 'VWO', 'metadata' and
'harvested'

But, to answer the questions --

1. a home-grown XML data store. (not using something COTS, as we didn't
find anything at the time that could handle matching numeric
ranges w/ units,
conversion between wavelength, frequency and electron volts, etc.)

That's for the registry -- for the granules, we have a few more:

Various SQL database (mySQL, PostgreSQL, Oracle)

Well-named files in a fixed directory structure.

And, because you never said 'good metadata management', we also
have
some dependancies on other formats, that I pull into SQL
databases, including:

NetDRMS (see http://jsoc.stanford.edu/netdrms )
FITS tables
IDL save files

2. It depends on what you consider 'access'. I assume you mean to the
registry, in which case, there's an API, but I haven't updated
the docs in a
while. (yes, the ticket's dated Sept 2005):

http://vso1.nascom.nasa.gov/docs/ticket/71

I tried re-implementing the API for JSON returns, but I wasn't
getting
consistent responses from all browsers (some not at all):

http://vso1.nascom.nasa.gov/jquery/registry_query.html

-Joe H.