Proposal for an online conditions database

• During data taking various conditions of the detector, electronics, data acquisition system, hall, and counting room will be recorded.
• These data will be recorded in different ways for different reasons, but one of the main uses is for use in subsequent data analysis.
• Things like magnet power supply currents, temperatures, trigger rate, scalers will all need to be available for offline processing.
• These quantities will need to identified by time of recording, run number, and perhaps event number.
• These quantities will not have to be recorded on an event-by-event basis; most will only be recorded once per run.

Proposed schema:

Features:

• Different processes can update quantities for which they are responsible independently.
  • Special events, e. g., scalers
  • Alarm systems
  • Log book
• Central server alone needs to know DAQ status (single number, the ID)
• New quantities can be added without re-writing the schema
• Frequency of update completely determined by the data producing client