tapquery
: Queries a Table Access Protocol server
tapquery
can query remote databases using the
Table Access Protocol (TAP) services by submitting
Astronomical Data Query Language queries to them and retrieving
the results.
TAP and
ADQL
are Virtual Observatory protocols.
Queries can be submitted in either synchronous or asynchronous mode,
as determined by the sync
parameter.
In asynchronous mode, if the query has not been deleted by the time the
command exits (see the delete
parameter),
the result can be picked up at a later stage using the
tapresume
command.
Table uploads are supported, so it is possible (if the service supports
this functionality), to upload a local table to the remote database,
perform a query involving it, such as a join with a remote table of some sort,
and receive the result. This powerful facility gives you crossmatches
between local and remote tables.
This command does not provide any facility for querying the service for either table or capability metadata, so you will need to know about the service capabilities and database structure from some other source (possibly TOPCAT).
Note: this command has been introduced at STILTS version 2.3, at which time most available TAP services are quite new and may not fully conform to the standards, and usage patterns are still settling down. For this reason you may find that some TAP services do not behave quite as expected; it is also possible that in future versions the command behaviour or parameters will change in line with changing service profiles or in the light of user experience.