- ifmt=<in-format>
Specifies the format of the input table as specified by
parameter
in. 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. This parameter is ignored for scheme-specified tables.
- istream=true|false
If set true, the input table specified by the
in
parameter will be read as a stream. It is necessary to give the
ifmt
parameter in this case. Depending on the required operations and processing
mode, this may cause the read to fail (sometimes it is necessary to read the
table more than once). It is not normally necessary to set this flag; in most
cases the data will be streamed automatically if that is the best thing to do.
However it can sometimes result in less resource usage when processing large
files in certain formats (such as VOTable). This parameter is ignored for
scheme-specified tables.
- in=<table>
The location of the input table. 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 ifmt
parameter. Note that not all formats can be streamed in this way.
- A scheme specification of the form
:<scheme-name>:<scheme-args>.
- 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.
- icmd=<cmds>
Specifies processing to be performed on the input table
as specified by parameter
in, 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, and lines which are blank
or which start with a '#' character are ignored.
- 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.
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, and lines which are blank
or which start with a '#' character are ignored.
- omode=out|meta|stats|count|checksum|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
- checksum
- 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".
- inlon=<expr/deg>
Longitude in degrees for the position of each row in the
input table. This may simply be a column name, or it may be an algebraic
expression as explained in SUN/256. The coordinate system must match that used
for the coordinates in the remote table.
- inlat=<expr/deg>
Longitude in degrees for the position of each row in the
input table. This may simply be a column name, or it may be an algebraic
expression as explained in SUN/256. The coordinate system must match that used
for the coordinates in the remote table.
- tapurl=<url-value>
The base URL of a Table Access Protocol service. This is
the bare URL without a trailing "/[a]sync".
In the usual case, 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.
In some cases however, determination of the endpoints is more
complicated, as determined by the interface parameter which may cause
endpoints to be read from the capabilities document at
tapurl/capabilities, and by other endpoint-specific parameters
(syncurl, asyncurl, tablesurl, capabilitiesurl,
availabilityurl, examplesurl) for fine tuning.
- interface=tap1.0|tap1.1|cap
Defines how the service endpoints and the version of the
TAP protocol to use for queries is determined. This may take one of the
following (case-insensitive) values:
- TAP1.0: The standard TAP endpoints are used, without examining the
service's capabilities document. The service is queried using version 1.0
of the TAP protocol.
- TAP1.1: The standard TAP endpoints are used, without examining the
service's capabilities document. The service is queried using version 1.1
of the TAP protocol.
- cap: The service's capabilities document is examined, and the
endpoints listed there are used.
The capabilities document, if used, is read from
tapurl/capabilities unless the capabilitiesurl parameter is
defined, in which case that is used.
The baseline value of all the TAP service endpoints (sync,
async, tables, capabilities, examples) are
determined by this parameter, but each of those endpoint values may be
overridden individually by other endpoint-specific parameters
(syncurl, asyncurl, tablesurl, capabilitiesurl,
availabilityurl, examplesurl)
For default (unauthenticated) access, the default value is usually
suitable.
- taptable=<name>
Name of the table in the given TAP service against which
the matching will be performed.
- taplon=<column>
Longitude in degrees for the position of each row in the
remote table. This is an ADQL expression interpreted within the TAP service,
typically just a column name. The coordinate system must match that used for
the input table.
- taplat=<column>
Latitude in degrees for the position of each row in the
remote table. This is an ADQL expression interpreted within the TAP service,
typically just a column name. The coordinate system must match that used for
the input table.
- tapcols=<colname,...>
Comma-separated list of column names to retrieve from the
remote table. If no value is supplied (the default), all columns from the
remote table will be returned.
- sr=<expr/deg>
Maximum distance in degrees from the local table
(lat,lon) position at which counterparts from the remote table will be
identified. This is an ADQL expression interpreted within the TAP service, so
it may be a constant value or may involve columns in the remote table.
- find=all|best|each|each-dist
Determines which pair matches are included in the result.
- all: All matches
- best: Matched rows, best remote row for each input row
- each: One row per input row, contains best remote match or
blank
- each-dist: One row per input row, column giving distance only for
best match
Note only the
all mode is symmetric between the two tables.
- blocksize=<int-value>
The number of rows uploaded in each TAP query. TAP
services may have limits on the number of rows in a table uploaded for
matching. This command can therefore break up input tables into blocks and
make a number of individual TAP queries to generate the result. This parameter
controls the maximum number of rows uploaded in each individual request. For
an input table with fewer rows than this value, the whole thing is done as a
single query.
- maxrec=<int-value>
Limit to the number of rows resulting from this
operation. If the value is negative (the default) no limit is imposed. Note
however that there can be truncation of the result if the number of records
returned from a single chunk exceeds limits imposed by the service.
- sync=true|false
Determines whether the TAP queries are submitted in
synchronous or asynchronous mode. Since this command uses chunking to keep
requests to a reasonable size, hopefully requests will not take too long to
execute, therefore the default is synchronous (true).
- blockmaxrec=<nrow>
Sets the MAXREC parameter passed to the TAP service for
each uploaded block. This allows you to request that the service overrides its
default limit for the number of rows output from a single query. The service
may still impose some "hard" limit beyond which the output row count
cannot be increased.
Note this differs from the maxrec parameter, which gives
the maximum total number of rows to be returned from this command.
- 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.
- fixcols=none|dups|all
Determines how input columns are renamed before use in
the output table. The choices are:
- none: columns are not renamed
- dups: columns which would otherwise have duplicate names in the
output will be renamed to indicate which table they came from
- all: all columns will be renamed to indicate which table they came
from
If columns are renamed, the new ones are determined by
suffix*
parameters.
- suffixin=<label>
If the
fixcols parameter is set so that input
columns are renamed for insertion into the output table, this parameter
determines how the renaming is done. It gives a suffix which is appended to
all renamed columns from the input table.
- suffixremote=<label>
If the
fixcols parameter is set so that input
columns are renamed for insertion into the output table, this parameter
determines how the renaming is done. It gives a suffix which is appended to
all renamed columns from the TAP result table.