STILTS-TAPQUERY(1)

📦
version 3.5.4 · 5 versions
, in ubuntu stonking

✨ STILTS-TAPQUERY(1) — the stilts tapquery manual, bestie edition 💅

okay so. you wanna talk to a remote astronomy database with ADQL and get a table back? this is THE command. it's from the Stilts commands family and it is, frankly, iconic.

🌸 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|checksum|cgi|discard|topcat|samp|tosql|gui]
                [out=<out-table>] [ofmt=<out-format>] [upnameN=<adql-
                identifier>] [tapurl=<url-value>]
                [interface=tap1.0|tap1.1|cap] [auth=true|false]
                [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|now]

look at that argument list. it's giving ✨thorough✨. anyway—

🦋 DESCRIPTION 🦋

so tapquery can query remote databases using the Table Access Protocol (TAP) services — you submit Astronomical Data Query Language (ADQL) queries to them and it hands you back the results. TAP and ADQL are Virtual Observatory protocols. no cap. Virtual Observatory protocols, bestie. 🌈

Queries can be submitted in either synchronous or asynchronous mode, and which one you get is decided by the sync parameter. In asynchronous mode, if the query has not been deleted by the time the command exits (peep the delete parameter for that whole situation), the result can be picked up at a later stage using the tapresume command. so it's not gone, it's just at brunch. 😌

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. 💖 local table x remote table, they met on TAP, it's a love story fr fr.

For services that require authentication, you will need to supply your credentials as described in SUN/256. Otherwise, queries will be submitted anonymously by default, but you can force a login attempt to services with optional authentication by setting auth=true. 💅

🫶 heads up bestie: 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). it's not gonna google the schema for you, okay? you gotta come prepared.

✨ OPTIONS ✨

🌸 the upload squad

  • 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. one big happy parameter family. 👑
  • 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. This parameter is ignored for scheme-specified tables. 💀 it tried its best and still had to snitch on itself.
  • 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 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. it just handles it. no thoughts, head empty, unzipped. ✨

  • 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 alternatively 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. A backslash character '\fR' at the end of a line joins it with the following line. 💅

🎀 the output pipeline

  • 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 alternatively 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. A backslash character '\fR' at the end of a line joins it with the following line. 🌸

  • 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. iykyk 💖

  • 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". don't be sneaky.
  • 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. 😭 it's a guesser, not a mind reader.
🫶 same deal: 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_]*). no spaces, no vibes, just that regex.

🌈 service stuff

  • 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). one parameter to set the vibe, six more to fight the vibe. that's just how it is.

For default (unauthenticated) access, the default value is usually suitable. 💜

  • auth=true|false — okay so if this is true, the command will try to authenticate with the TAP service even if anonymous operation is permitted. If the service offers authentication, you’ll get asked for credentials. ngl for non-interactive contexts you might want auth.username and auth.password system properties. ✨
  • adql=<query-text> — ADQL string that says which TAP query to execute. ADQL/S is like SQL, so this string will likely start with "SELECT". periodt 💅
  • parse=true|false — decides whether an attempt will be made to check the ADQL syntax before submitting the query. If it’s true, and a syntax error is found, the task fails with an error before any attempt is made to submit the query. iconic, honestly. 🦋
  • sync=true|false — decides if the TAP query is submitted synchronous or asynchronous. Synchronous (true) means the result is retrieved over the same HTTP connection the query is submitted from. Uncomplicated, but if the query takes a long time it may time out and the results will be lost. Asynchronous (false) means 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. vibe check: default false! 🎀
  • maxrec=<nrow> — sets the requested maximum row count for the result of the query. The service is not obliged to respect this, but if 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. trade-offs, bestie. ✨
  • 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. iykyk 🦋
  • 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. so don’t try it, bestie. 💅
  • 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. we’ve all been there. 🍓
  • progress=true|false — if this parameter is set true, updates on the status of the asynchronous UWS job are reported to standard output as they become available. This parameter is ignored in synchronous mode. main character energy only for async. 👑
  • delete=finished|never|always|now — 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 or using tapresume 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 on command exit
    • now — delete and return immediately

✨ SEE ALSO ✨

  • stilts(1)
  • If the package stilts-doc is installed, the full documentation SUN/256 is available in HTML format: file:///usr/share/doc/stilts/sun256/index.html

💖 VERSION 💖

  • STILTS version 3.5.4-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 🌈

  • Mark Taylor (Bristol University)

and that’s the whole page, bestie 💅 — Mar 2017, STILTS version 3.5.4-debian, page STILTS-TAPQUERY(1).

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