A type of IVOA resource describing (exactly) one database independently of
any service giving access to the database. The mandatory core of the element
details the database itself. There may, optionally, be additional elements
describing the provenance and astronomical usage of the resource.
The structure of the database. There may be detailed metadata for zero or more tables,
and these are intended to be read by software. The must also be a human-readable
description and a name. A db:DB element with no tables could be used to
register a database for which the detailed schemata have not yet been worked out.
State the formal name of the database by which it is known to the DBMS.
This may be different to the name of the resource as specified in the
http://www.ivoa.net/xml/VOResource/v0.10 namespace; the latter is for
human reader and the current element is for the machines.
Describe any special features of the database, if any. This description
should avoid scientific description of the data collection as a whole
(that is better put in the {http://www.ivoa.net/xml/VOResource/v0.10}Content
structure). The description should also avoid duplicating the structural
description of the tables in the {http://www.ivoa.net/xml/VODataService/v0.5}Table
elements. If there is sublety about the relationship of the tables in the database,
then describe it here.