Current Standards

* Registry standard developed by the DAL working group.

** Interest group developed standard endorsed and administered by the DAL working group.

Ongoing Work

Rationale

The task of the DAL working group is to define and formulate VO standards for remote data access. Client data analysis software will use these services to access data via the VO framework; data providers will implement these services to publish data to the VO. The DAL working group will define the scope of the DAL standards, outline a process by which DAL standards are defined, and generate the initial version 1.0 of the DAL standard. This standard will provide guidance to data centers and survey projects when designing VO compliant interfaces. It will allow them to justify the allocation of resources for its implementation and maintenance. Once the work on Version 1.0 is accomplished the working group will coordinate future development of the standard.

Current Activities

• DALI-1_1-Next
• SODA
• AccessData (legacy) now SODA
• Image Access (SIA)
• Data Linking (DataLink)
• Table Access Protocol (TAP)
• Astronomical Data Query Language (ADQL)
• Simple Cone Search
• Spectral Data (SSA)
• Time Series Data (Light Curves)
• Footprint Access Protocol
• TAPImplementationNotes
• DALI-1_0-Next
• SimDAL

DAL future

• Feedback, prototypes, ideas and proposals

Idle or Abandoned

• Parameterised Query Language (PQL)

Past Activities

• Data Access Layer Interface (DALI)
• TAP Registry Extension (TAPRegExt)
• SSA-1.1 RFC
• Spectral Line Lists
• VO Query Language

WG Roadmap

• Current DAL roadmap on TCG page: http://wiki.ivoa.net/twiki/bin/view/IVOA/2013BRoadmap#Data_Access_Layer

• Roadmap History
  • Current DAL Roadmap (May 2007) status May 2006 (.pdf) status May 2005 (.pdf) status June 2004 (.pdf) overview May 2004 (.pdf)

Notes on Defining a DAL Standard

This page contains some ideas and definitions to help frame the definition of DAL standards. To be discussed.

Notes on Defining new service parameters

This page contains some hints to help defining new service paremeters accordig to the 3 factor semantics.

Recommended reading

• Simple Image Access Protocol (SIA-1.0)
• Table Access Protocol (TAP-1.0)
• Astronomical Data Query Language (ADQL-2.0)
• Cone Search Protocol (ConeSearch-1.03)
• Simple Line Access Protocol (SLAP-1.0)
• Simple Spectral Access Protocol (SSA-1.04)
• DAL mail archive

How to contribute

• subscribe to dal@ivoa.net and share your ideas
• register with the IVOA Twiki and edit this or add new pages
• contact FrancoisBonnarel and MarcoMolinaro to propose creation of a new DAL standard.