IVOA 2010, Nara TAP implementation on SimDB Application to DEUVO Jonathan Normand VO-Paris Data Centre

IVOA 2010, Nara2 Access to data of simulation Problematic: o As many ways as types of simulation o Steps depend on type of simulation PDR: Protocol Parameters StarFormat: Project Experience Snapshot Postprocessings As many ways as simulations and users Solutions: o Ask data directly to the scientist o Use the web UI provided for each simulation Based on vo-urp framework: create database from SimDM, generate classes to access it, build web UI from them o Use TAP layer

IVOA 2010, Nara3 DEUVO Steps to access to data of DEUVO o Select simulation Depends on cosmology, code, physics... o Select snapshot o Select post processing Depends on object, postprocessor and parameters o Select properties Use a different way than PDR or StarFormat

IVOA 2010, Nara4 DEUVO – vo-urp solution From scratch o Need to know many technologies (JAVA, JSP Servlet…) and classes generate by vo-urp (javadoc is available) It is a long way Adapt the web UI developed for StarFormat to DEUVO needs o Steps differ too much so lot of code in classes has to be modified o SimDB of StarFormat and DEUVO are different so queries on database are different Need to modify almost all queries Try to use a more standardized way: TAP

IVOA 2010, Nara5 DEUVO – TAP (1/2) Expected Metadata o Provide TAP_SCHEMA or VOSI-tables output of SimDB o SimDB created from SimDM: ~40 tables and many fields Can everyone understand this kind of metadata?

IVOA 2010, Nara6 DEUVO – TAP (2/2) Query data o Write query in the request o Example of query (without many constraints): SELECT s.id as id, s.publisherdid as publisherdid, s0.value_asquantity_value as mass, s1.value_asquantity_value as x, s2.value_asquantity_value as y, s3.value_asquantity_value as z FROM snapshot s, objectcollection o, statistics s0, statistics s1, statistics s2, statistics s3 WHERE s.containerid = 6 AND o.containerid = s.id and s0.containerid = o.id and s1.containerid = o.id and s2.containerid = o.id and s3.containerid = o.id and s0.publisherdid = 'mass' and s1.publisherdid = 'x' and s2.publisherdid = 'y' and s3.publisherdid = 'z o Corresponding VIEW (simple and readable): SELECT id, publisherdid, mass, x, y, z FROM tapview WHERE containerid = 6 Need to provide views for each allowed queries

IVOA 2010, Nara7 DEUVO – TAP problems Access step by step is not possible Are people who not know the DM able to write a query ? o Knowledge of simulation DM is mandatory to make a meaningful query Technical limit: length of URL (browser)

IVOA 2010, Nara8 Conclusions Developer point of view: oNeed to provide views to help the end user oEasy to add a TAP layer: handle TAP request and execute the query passed in parameters User point of view: oKnowledge of DM and simulation helps to write queries TAP is not self sufficient oProvide a step by step form on top of TAP oForm helps to write queries for the user