The LHCb configuration database

The Experiment Control System (ECS) will handle the monitoring, configuration and operation of all the LHCb experimental equipment. All parameters required to configure electronics equipment under the control of the ECS will reside in a configuration database. The database will contain two kinds of information: 1. Configuration properties about devices such as hardware addresses, geographical location, and operational parameters associated with particular running modes (dynamic properties). 2. Connectivity between devices : this consists of describing the output and input connections of a device (static properties). The representation of these data using tables must be complete so that it can provide all the required information to the ECS and must cater for all the subsystems. The design should also guarantee a fast response time, even if a query results in a large volume of data being loaded from the database into the ECS. To fulfil these constraints, we apply the following methodology: Determine from the dataflow the list of all devices in the subsystem and the connections between devices, Collect use cases and apply the $Entity$ $Relationship$ $Model$ to design the schema of the tables, Define an API allowing users to interact with the database according to the use cases, Implement the API and create tools. The configuration database is a relational database which has been implemented using Oracle. A part of the configuration database is built using the Database tool developed in common for the four LHC experiments by JCOP (Joints Controls Project). To test the configuration database design we have integrated it into the LHCb TFC and DAQ systems.