Ubuntu Manpage: stilts-tapquery - Queries a Table Access Protocol server

NAME

       stilts-tapquery - Queries a Table Access Protocol server

SYNOPSIS

       stilts tapquery [nupload=<count>] [ufmtN=<in-format>] [uploadN=<tableN>] [ucmdN=<cmds>]
                       [ocmd=<cmds>]
                       [omode=out|meta|stats|count|cgi|discard|topcat|samp|tosql|gui] [out=<out-
                       table>] [ofmt=<out-format>] [upnameN=<adql-identifier>] [tapurl=<url-
                       value>] [adql=<query-text>] [parse=true|false] [sync=true|false]
                       [maxrec=<nrow>] [destruction=<iso8601>] [executionduration=<seconds>]
                       [compress=true|false] [upvotformat=TABLEDATA|BINARY|BINARY2]
                       [language=<lang-name>] [poll=<millisec>] [progress=true|false]
                       [delete=finished|never|always]

DESCRIPTION

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.

OPTIONS

nupload=<count>
The number of upload tables for this task. For each of the upload tables N there
will be associated parameters ufmtN, uploadN and ucmdN.

ufmtN=<in-format>
Specifies the format of upload table #N as specified by parameter uploadN. The
known formats are listed in SUN/256. This flag can be used if you know what format
your table is in. If it has the special value (auto) (the default), then an attempt
will be made to detect the format of the table automatically. This cannot always be
done correctly however, in which case the program will exit with an error
explaining which formats were attempted.

uploadN=<tableN>
The location of upload table #N. This may take one of the following forms:

* A filename.

* A URL.

* The special value "-", meaning standard input. In this case the input format
must be given explicitly using the ufmtN parameter. Note that not all formats
can be streamed in this way.

* A system command line with either a "<" character at the start, or a "|"
character at the end ("<syscmd" or "syscmd|"). This executes the given pipeline
and reads from its standard output. This will probably only work on unix-like
systems.
In any case, compressed data in one of the supported compression formats (gzip,
Unix compress or bzip2) will be decompressed transparently.

ucmdN=<cmds>
Specifies processing to be performed on upload table #N as specified by parameter
uploadN, before any other processing has taken place. The value of this parameter
is one or more of the filter commands described in SUN/256. If more than one is
given, they must be separated by semicolon characters (";"). This parameter can be
repeated multiple times on the same command line to build up a list of processing
steps. The sequence of commands given in this way defines the processing pipeline
which is performed on the table.

Commands may alteratively be supplied in an external file, by using the indirection
character '@'. Thus a value of "@filename" causes the file filename to be read for
a list of filter commands to execute. The commands in the file may be separated by
newline characters and/or semicolons.

ocmd=<cmds>
Specifies processing to be performed on the output table, after all other
processing has taken place. The value of this parameter is one or more of the
filter commands described in SUN/256. If more than one is given, they must be
separated by semicolon characters (";"). This parameter can be repeated multiple
times on the same command line to build up a list of processing steps. The sequence
of commands given in this way defines the processing pipeline which is performed on
the table.

omode=out|meta|stats|count|cgi|discard|topcat|samp|tosql|gui
The mode in which the result table will be output. The default mode is out, which
means that the result will be written as a new table to disk or elsewhere, as
determined by the out and ofmt parameters. However, there are other possibilities,
which correspond to uses to which a table can be put other than outputting it, such
as displaying metadata, calculating statistics, or populating a table in an SQL
database. For some values of this parameter, additional parameters (<mode-args>)
are required to determine the exact behaviour.

Possible values are

* out

* meta

* stats

* count

* cgi

* discard

* topcat

* samp

* tosql

* gui
Use the help=omode flag or see SUN/256 for more information.

out=<out-table>
The location of the output table. This is usually a filename to write to. If it is
equal to the special value "-" (the default) the output table will be written to
standard output.

This parameter must only be given if omode has its default value of "out".

ofmt=<out-format>
Specifies the format in which the output table will be written (one of the ones in
SUN/256 - matching is case-insensitive and you can use just the first few letters).
If it has the special value "(auto)" (the default), then the output filename will
be examined to try to guess what sort of file is required usually by looking at the
extension. If it's not obvious from the filename what output format is intended, an
error will result.

This parameter must only be given if omode has its default value of "out".

upnameN=<adql-identifier>
Identifier to use in server-side expressions for uploaded table #N. In ADQL
expressions, the table should be referred to as "TAP_UPLOAD.<label>".

The value must syntactically be an ADQL identifier ([A-Za-z][A-Za-z0-9_]*).

tapurl=<url-value>
The base URL of a Table Access Protocol service. This is the bare URL without a
trailing "/[a]sync".

The default values of the various endpoints (sync and async query submission,
tables metadata, service-provided examples etc) use this URL as a parent and append
standard sub-paths. However, other parameters (syncurl, asyncurl, ...) are provided
so that the different endpoints can be set individually if required.

adql=<query-text>
Astronomical Data Query Language string specifying the TAP query to execute. ADQL/S
resembles SQL, so this string will likely start with "SELECT".

parse=true|false
Determines whether an attempt will be made to check the syntax of the ADQL prior to
submitting the query. If this is set true, and if a syntax error is found, the task
will fail with an error before any attempt is made to submit the query.

sync=true|false
Determines whether the TAP query is submitted in synchronous or asynchronous mode.
Synchronous (true) means that the result is retrieved over the same HTTP connection
that the query is submitted from. This is uncomplicated, but means if the query
takes a long time it may time out and the results will be lost. Asynchronous
(false) means that the job is queued and results may be retrieved later. Normally
this command does the necessary waiting around and recovery of the result, though
with appropriate settings you can get tapresume to pick it up for you later
instead. In most cases false (the default) is preferred.

maxrec=<nrow>
Sets the requested maximum row count for the result of the query. The service is
not obliged to respect this, but in the case that it has a default maximum record
count, setting this value may raise the limit. If no value is set, the service's
default policy will be used.

destruction=<iso8601>
Posts an updated value of the UWS DESTRUCTION parameter to the query job before it
starts. This only makes sense for asynchronous jobs (sync=false).

The supplied value should be an ISO-8601-like string, giving the new requested job
destruction time. The service is not obliged to honour this request. See UWS v1.0,
sec 2.2.3.3.

executionduration=<seconds>
Posts an updated value of the UWS EXECUTIONDURATION parameter to the query job
before it starts. This only makes sense for asynchronous jobs (sync=false).

The supplied value is an integer giving the maximum number of wall-clock seconds
for which the job is permitted to execute before being forcibly terminated. A value
of zero indicates unlimited duration. The service is not obliged to honour this
request. See UWS v1.0, sec 2.2.3.4.

compress=true|false
If true, the service is requested to provide HTTP-level compression for the
response stream (Accept-Encoding header is set to "gzip", see RFC 2616). This does
not guarantee that compression will happen but if the service honours this request
it may result in a smaller amount of network traffic at the expense of more
processing on the server and client.

upvotformat=TABLEDATA|BINARY|BINARY2
Determines how any uploaded tables will be serialized for transmission to the TAP
server. The supplied string is the name of one of the defined VOTable serialization
formats. The choice shouldn't affect any results, though it may affect required
bandwidth, and some services may (though should not) have non-standard requirements
for serialization format.

language=<lang-name>
Language to use for the ADQL-like query. This will usually be "ADQL" (the default),
but may be set to some other value supported by the service, for instance a variant
indicating a different ADQL version. Note that at present, setting it to "PQL" is
not sufficient to submit a PQL query.

poll=<millisec>
Interval to wait between polling attempts, in milliseconds. Asynchronous TAP
queries can only find out when they are complete by repeatedly polling the server
to find out the job's status. This parameter allows you to set how often that
happens. Attempts to set it too low (<50) will be rejected on the assumption that
you're thinking in seconds.

progress=true|false
If this parameter is set true, progress of the job is reported to standard output
as it happens.

delete=finished|never|always
Determines under what circumstances the UWS job is to be deleted from the server
when its data is no longer required. If it is not deleted, then the job is left on
the TAP server and it can be accessed via the normal UWS REST endpoints until it is
destroyed by the server.

Possible values:

* finished: delete only if the job finished, successfully or not

* never: do not delete

* always: delete in any case

VERSION

       STILTS version 3.1-2-debian

       This is the Debian version of Stilts, which lack the support  of  some  file  formats  and
       network protocols. For differences see
       file:///usr/share/doc/stilts/README.Debian

AUTHOR