IVOA Virtual Observatory Query Language (VOQL) Working Group

RFC

The Request For Comments period starts on 26 Apr 2008. Please access the RFC Pages to introduce your comments.

Contents

Introduction

Definition: The IVOA Query Language group will be in charge of defining a universal Query Language to be used by applications accessing distributed data within the Virtual Observatory framework.

Group members and how to join.

Anyone can belong to the IVOA VOQL Working Group. You can Subscribe to the VOQL mailing list and participate in the discussions held in that list.

VOQL Technical Experts Group (VOQL-TEG)

The VOQL Technical Experts group (VOQL-TEG) was created in Sep 2006 with the aim of defining the technical specification of the standards, making sure that the proposed solutions both fulfil the user community needs and are technically feasible. There is a mailing list for this group (voql-teg@ivoa.net). Only members of the VOQL-TEG can send mails to this list. However, anyone can look at the archived mails for information (See forum list).

The VOQL-TEG holds a monthly meeting where details on the standards, specifications, etc. are discussed. The Minutes of these meetings can be seen in the aforementioned mailing list.

VOQL-TEG Members

The VOQL-TEG was formed with a member from each of the institutions belonging to the IVOA that had shown technical expertise in the field and who were willing to spend resources in the active participation within the group.

The following is a list of the VOQL-TEG members together with their affiliation:

• Alex Szalay (NVO)
• Francois Ochsenbein (CDS)
• Jeff Lusted (AstroGrid)
• Pat Dowler (CVO)
• Yuji Shirasaki (JVO)
• Inaki Ortiz (ESAVO)
• Benjamin Gufler (GAVO)

• Pedro Osuna (IVOA VOQL Chairman)

The chairman of the Data Access Layer group (Doug Tody) is invited to all the VOQL-TEG meetings (see below details).

New planned structure for the VOQL group and deliverables.

According to recent discussions, the VOQL standards structure has been refurbished to clearly show a separation of Language, Protocol and Service. The new structure and the items the VOQL group will be dealing with are therefore:

1.- The Language.

This will be a refurbishing of the current ADQL able to accomodate different communities' needs. A document only dealing with the Language specification will be produced.

2.- The Protocol.

This will deal with how to access data using the ADQL language. A new document will be produced for this so called Table Access Protocol (TAP). The chair of the Data Access Layer group is a permanent member of the VOQL-TEG to co-author the initial creation of this protocol

3.- The Service.

This will deal with the important issue of Cross-match. A new document will be produced for a type of services dealing directly with cross-matching of sources (of whichever type). This work will be initiated within the VOQL-TEG and evolved in conjunction with other IVOA groups.

Expected deliveries:

1.- Refurbished ADQL doc in quite a mature state by China 2007 interop.

2.- First draft of the Table Access Protocol (TAP) doc by China 2007 interop.

Further discussions are needed to estimate possible due dates for crossmatch service specification.

Roadmap

Action	When	Who
Astronomical Data Query Language (ADQL)
Refurbished ADQL Draft	China Interop meeting 2007	VOQL-TEG
Table Acces Protocol
First draft specification	China Interop meeting 2007	VOQL-TEG
Cross-match Service
Create new spec	China Interop meeting 2007	VOQL-TEG

Old Group pages and documents.

The initial pages with the whole set of documents and pointers to meetings, discussions, etc. can be found here.

The decision has been taken to start the current Wiki pages from scratch in order to make the separation of the different VOQL tasks (see above "New planned structure for VOQL") clearer.

• ADQL-20070903.pdf: Draft Update 03/09/2007

• ADQL-20070918.pdf: Draft update 18/09/2007 (Before Cambridge Interop)

• adql-bnf-20080318.html: ADQL BNF in HTML format

• adql-bnf-20080325.html: ADQL BNF in HTML format v1.5-20080318

• ADQL-20080415.pdf: Draft update 15/04/2008 - Small typos corrected

• adql-bnf-20080415.html: BNF in HTML format v1.5-20080415 - Typos corrected

• ADQL-v2.0-20080430.pdf: Draft update 15/04/2008 - New version number

• adql-bnf-v2.0-20080430.html: BNF in HTML format v2.0-2008043 - New version number

• ADQL-v2.0-20080908.pdf: Draft update 08/09/2008 - After RFC

• adql-bnf-v2.0-20080908.html: BNF in HTML format v2.0-20080908 - After RFC

• adql-bnf-v2.0-20081028.html: BNF in HTML format v2.0-20081028 - Baltimore

• ADQL-v2.0-20081028.pdf: Draft update 28/10/2008 - Baltimore Interop

• adql-bnf-v2.0.html: BNF in HTML format v2.0 - IVOA Recommendation

• ADQL-v2.0.pdf: ADQL v2.0 - IVOA Recommendation