1. An invention comprising a method of managing finite data storage of a temporal data store comprising one or more data groups, each data group comprising a plurality of members, data of each of which is preserved in the finite data storage, each data group having associated therewith a time point and each member of each data group having associated therewith a preservation weight, the method comprising the step of, upon detecting that consumption of the finite data storage has reached a first level, then, in order of increasing preservation weight beginning with the one or more members having the lowest preservation weight, successively deleting each member in increasing chronological order beginning with the oldest member first, until the finite data storage consumption has reached a second level.