Addressing the persistency patterns of the time evolving HEP data in the ATLAS/LCG MySQL Conditions Databases
Pedro, L, Klose, D, Franco, T, N. Barros, D. Düllmann, A. Amorim, Andrea Valassi · CERN Document Server (European Organization for Nuclear Research) · 2005
This paper describes the main developments introduced in the revised Conditions Database Interface deployed against the MySQL backend.The need for considering the different patterns of archiving and organizing the information along the time path is explained and the specific solutions introduced in the Conditions Interface to deal with the time interval and version description of conditions objects is discussed.The requirement of simultaneously sharing data among different applications in different environments, that share only the Conditions Database interface in common, motivated us to create a commonly used generic class for data that generalizes the relational table and that is independent of the object streaming solutions used.This not only allows the access to data that is not hidden by the serialization in some specific framework, but also enables the table projection and restriction on the database server for user data.The future directions of investigation to interface this generalized container to the user in different frameworks are discussed.The issue of distributed data storage and partitioning among long periods of time, is also addressed.