Permissions

All databases will be world-readable.

Table of write-permissions:

• expert groups means unix groups like ps-xpp, psdata
• there will be cross-hutch-expert protection: e.g. ps-xpp won't have permission to write to the TMO databases
• Murali has said experts may have to do an extra step (e.g. set an environment variable) in order use a different URL/end-point for expert-group access

Calibration Database Access Patterns

• segment-specific calibrations will access run-dependent constants using detectorType_segmentSerialNumberString, where segmentSerialNumber is either read from the detector hardware by the daq (ideal, like epix) or managed administratively (more difficult)
• detector-specific calibrations (e.g. geometry, hexanode roentdek algorithm, "pop" electron image inversion algorithm) will access run-dependent constants using detectorType_allSegmentSerialNumberString, where both halves of that field are administratively managed.
• if a detector has only one segment the segment-specific/detector-specific calibrations are the same (but we should only have one copy)
• could put segment hardware version number information as xtc payload
• this means that multi-segment detectors will need to do multiple database fetches (bad) but that detector segments can be shuffled around without changing the calib database (good)
• calibration constants should not be exposed to ami, but only used internally by the detector interface or the algorithm