Introduction

DataAccess is concerned with how DataSets are published onto AstroGrid. Work includes:

• Publishing real DataSets. Keep the number small but varied for most of AstroGrid1, so we don't spend too much time maintaining them.

• Developing code, HowTo documents, etc for a Publisher's Astrogrid Library (PAL), that could be used by DataSet owners to publish their data. Major code components include:
  • DataAccess service
  • DataAccess delegate(s)
  • UI - portal pages for building queries

• Resolve interoperability problems at two levels - within AstroGrid to get a working system up in a year or two, and internationally with IVOA etc for long term solutions. Areas include:
  • Query Language (VOQL). The IVO VOQL is still in development; in the meantime we will use a DataAccessQuerySet (DAQS).
  • Describing data (ontology, UCDs)
  • Data formats (VOTable, FITS, FITS++?) for result sets.
  • Data streaming formats & mechanisms
  • Data nybbling - streaming data eg for doing Joins.

• Interfaces with other AstroGrid components are:
  • Job Manager (calls DataAccess)
  • Security (DataAccess uses to check whether user can access the data)
  • MySpace (publishing results, see DataAccess2MySpace)
  • Registry? (I think at the moment this interface is manual - ie the DataSet owner has to enter details into the Registry)

-- MartinHill - 25 Jul 2003

Proposals

• QueryObjectModelProposal - proposal for an object model for building / representing queries passed to the Dataset access service. -- NoelWinstanley - 27 Aug 2003