A short course on the VO's SQL-like query language, the Astronomical
Data Query Language. It also covers basic operation of some TAP user
agents. It is available as a multipage HTML rendering for online
perusal as well as a one-file PDF.
The NASA/IPAC Extragalactic Database (NED) provides a comprehensive fusion
of multi-wavelength data for hundreds of millions of objects located beyond
the Milky Way galaxy. As new observations are published in NASA mission
archives, journal articles and sky survey catalogs, they are cross-identified
with prior measurements and integrated in a unified database. Numerous derived
quantities are also provided to facilitate scientific research. For more
information see http://ned.ipac.caltech.edu/
