ADQL and PostgreSQL queries in the new framework

One of the new features in the new Daiquiri framework is the support of the Astronomical Data Query Language v2.0 (ADQL). This version of the SQL was designed specifically to be used in astronomy and comes with statements that facilitate cone-search queries and other positional selections. All ADQL queries that are submitted for the execution are translated to PostgreSQL dialect before they are passed to the database server. Users can also choose to write their queries in the PostgreSQL directly. In some cases this is more desirable since the ADQL does not support all features that are available in PostgreSQL, namely working with array structures.

As an example let us write an ADQL query that selects stars around the M4 globular cluster from the Gaia DR1 main table:

SELECT ra, dec
FROM gdr1.gaia_source
WHERE 1 = CONTAINS(POINT('ICRS', ra, dec),
                   CIRCLE('ICRS',4.2917,-0.4629, 0.008))

The cone selection is done using the CONTAINS statement. Alternatively, we can rewrite the same query using the PostgreSQL dialect in the following way:

SELECT ra, dec
FROM gdr1.gaia_source
WHERE pos @ scircle(spoint(4.2917,-0.4629), 0.008)

Here we use the PgSphere functions ‘scircle’ and ‘spoint’ to define the region. We connect the column containing the positional information (right ascension and declination) ‘pos’ to the cone selection with the @ operator. To learn more about the available PgSphere functions and capabilities please refer to the documentation here.

Migration to the new Gaia@AIP

On 18 April 2018 we updated Gaia@AIP to the new version of our Daiquiri framework. We also switched from MariaDB to PostgreSQL for the underlying database system. We removed a few older data sets (Gaia mock data). The external catalogs like UCAC5, RAVE DR5 and TYCHO2 are temporarily removed from the database and will be restored soon. Right now only GDR1 is available with GDR2 arriving on 25 April 2015.

We migrated your personal accounts and the metadata of all your jobs to the new system, but due to the changes to the database system we only restored the result tables querying GDR1.

While of all your jobs in the job list in the query interface should have been successfully restored, some might show an error. In most cases this is because the queried schema (an external catalogue) is not available anymore or temporarily.

Even if not all job results are available, you can still retrieve all of your queries. In the new system, this can be done in a more convenient way using the verbose job list (accessible through a link on the bottom of the job list in the query interface. This list can also show your removed jobs, which we now call archived.

If you need access to the older data sets like GUMS10 or GOG11, or need further assistance, please don’t hesitate to contact us through the contact form.

Gaia in the news

Hier ein deutscher Artikel bei heise.de:
ESA-Weltraumteleskop Gaia: Erste Himmelskarte mit einer Milliarde Sternen

Gaia Data Release 1 – now available!

The first Gaia data release GDR1 is now available for the public. The AIP hosts the Gaia data as one of the external data centers along with the main Gaia archive maintained by ESAC.

Watch the Press Conference from ESA’s Gaia Mission .

Gaia@AIP hosts the data from Gaia data releases in sharded MariaDB database nodes. The data can be queried directly using the Structured Query Language SQL, so you can retrieve only the data subset you interested in. After registration, you can use the Query Form to perform your query. We also prepared a set of examples for you to get started.

For more information please look up the Documentation or for even more details GAIA DATA RELEASE 1 (GAIA DR1) at ESA.

Press event and archive opening at ESAC

A press event will take place at ESAC on the day of the release (September 14) which you will be able to follow through Youtube (details will follow later). During the press event the Gaia archive will be opened and this will happen at 12.30 CEST.

The url for the archive will be

http://archives.esac.esa.int/gaia/

On Sep 14 there will also be a new release of Gaia Sky (with the TGAS catalogue included) so that everyone can do their own animations.

GDR1 – to be released mid September

The first Gaia data release is almost there. The archive will be opened to the public on 14th of September at 12:30 simultaneously at ESAC archive and the external data centres.