The invention relates to a method, apparatus and computer program for reducing
the number of data elements checkpointed in a system having at least one data store
where operations on said at least one data store are recorded in a log. A point
in the log is recorded. The oldest data element in each of the least one data store
is determined and it is then determined for each of the at least one data store
whether a logged representation of the data store's oldest data element is more
recent than the point recorded. Responsive to determining that a data store's logged
representation is more recent than the point recorded, it is realised that it is
not necessary to force data elements from that data store to disk if the point
recorded is made the point of restart for that data store.