Speaker
A. Amorim
(FACULTY OF SCIENCES OF THE UNIVERSITY OF LISBON)
Description
The size and complexity of the present HEP experiments
represents an enormous effort in the persistency of data. These efforts imply
a tremendous investment in the databases field not only for the event data
but also for data that is needed to qualify this one - the Conditions Data.
In the present document we'll describe the strategy for addressing the
Conditions data problem in the ATLAS experiment, focusing in the ConditionsDB
MySQL for the ATLAS/LCG project. The need for a persistent engine for
structured conditions data has motivated the studies for an relational backend
that maps transient structured objects in the relational database persistent
engine. This paper illustrate the proposal for the storage of Conditions data
in the LCG framework using it both to store only the Interval Of Validity
(IOV) and a reference that represents the 'path' to an external
persistent storage mechanism, and to archive the IOV and the data in
relational tables mapping the costumizable CondDBTable objects. This allow to
take advantages of all the relational features and also to
directly map between transient objects and tables in the database server.
The issue of distributed data storage and partitioning, is also analyzed in
this paper, taking into account the different levels of indirection that are
provided by the ConditionsDB MySQL implementation. These features represent a
very important built in functionality in terms of scalability, data balance
in a system that aims to be completely distributed and with a very high
performance for hundreds of users.
Primary authors
A. Amorim
(FACULTY OF SCIENCES OF THE UNIVERSITY OF LISBON)
A. Valassi
(CERN)
D. Duellmann
(CERN)
D. Klose
(FACULTY OF SCIENCES OF THE UNIVERSITY OF LISBON)
L. Pedro
(FACULTY OF SCIENCES OF THE UNIVERSITY OF LISBON)
N. Barros
(FACULTY OF SCIENCES OF THE UNIVERSITY OF LISBON)
T. Franco
(FACULTY OF SCIENCES OF THE UNIVERSITY OF LISBON)
