Apr 1, 2000
An OO tag database for physics analysis at HERA
A persistent object database based on Objectivity/DB was used
for the first time in a running high-energy physics environment
in the ZEUS experiment at the HERA electron-proton collider.
An event tag database of 250 physical variables per event is
created during offline event reconstruction and is later used
to rapidly select events for physics analysis. Around 100 million
events from 5 years of data are currently stored. The environment,
the design choices and the tag database system are described,
and the favourable users' experience is reported.