Observation metadata handling system at the European Southern Observatory

We present the design of the system for handling observations metadata at the Science Archive Facility of the European Southern Observatory using Sybase ASE, Replication Server and Sybase IQ. The system has been reengineered to enhance the browsing capabilities of Archive contents using searches on any observation parameter, for on-line updates on all parameters and for the on-the-fly introduction of those updates in files retrieved from the Archive. The systems also reduces the replication of duplicate information and simplifies database maintenance.