Patent ID: 7912817

Claim:
A computer-implemented method comprising: decomposing by a data maintenance computer system a type of data item by identifying constituent units of the data item; creating by a data maintenance computer system a shelf-life criterion for the constituent units by assigning one or more priority dimensions to each data item and to each constituent unit, establishing one or more data life dimensions applicable to all the data items and constituent units of the data item type; for each of a plurality of data items of the data item type currently stored by data storage system, wherein the data items occupy an amount of computer storage, establishing relationship factors for each of a plurality of data items to other data items, between constituent units within data items, and between data items, and periodically calculating or periodically updating by a data maintenance computer system a decomposability index for each constituent unit as a function of the priority dimensions and the data life dimensions, wherein the decomposability indices are additionally moved towards a threshold for constituent units which are reproducible, and wherein the calculating or updating a decomposability index comprises applying a relationship factor according to the relationship factors; and subsequent to the step of calculating or updating, decaying by a data maintenance computer system the data type by periodically deleting from the computer storage all constituent units which have decomposability indices exceeding a configured threshold, the decay reducing the amount of computer storage occupied by a remaining plurality of data items of the data type.