Use Case:  Retrieve Entity

All subsystems will use the archive as a persistent store for the entities they have under control. Entities will be created, updated retrieved and queried but usually not deleted. Allactivities have to be permitted. The 'retrieve' activity is used to retrieve complete entities from the archive.

Goal: Retrieve complete entities

Contact Author: A.Wicenec

Role(s)/Actor(s):

Primary: Any ALMA subsystem
Secondary: Executive, UserAdmin

Priority: Critical

Performance: Seconds (depending on the size of the entity).

Frequency: 1 Hz

Preconditions: 

  1. Database is running
  2. User got authenticated
  3. User has a UID

 Basic Course: 
  1. Subsystem establishes connection to archive, for a human user there is an user interface which acts as a subsystem. The subsystem is required to choose the correct interface, i.e. XMLStore, MonitorStore or BulkStore. This is not critical, because only a fewsubsystems will need to use the MonitorStore and the BulkStore.
    Alternate Course: none
    Exception Course: Connection can't be established: try again until timeout.
    Postcondition: Connection established.
  2. Send UID to retrieve interface.
    Alternate Course: use higher level interface (DAO) which maps user request into UID request.
    Exception Course: Retrieve failed: This is a fatal exception!
    Postcondition: Subsystem receives complete entity
Postconditions: 
  1. Subsystem retrieved complete entity.

Issues to be Determined or Resolved: 

The communication of the user ID and the associated permissions have to be clarified. The required level of granularity for permissions has to be specified by SSR and operational requirements.

Last modified: Thu Sep 25 16:12:29 CEST 2003