This table holds the abstract IDs for the artefact group. An artefact group consists of a name (see artefact_group_name) and a list of members (see artefact_group_member). It is up to the user to determine what an artefact group is meant to do functionally. Typically we assume that when one member of a group is transformed, all members of the group will also be transformed accordingly. The responsibility for such operations, however, lies downstream from the database (i.e., there are no database triggers involved with artefact groups).