US Patent 7631019 Distributing data across different backing data stores

A method and apparatus for distributing data across multiple data stores are provided. In one embodiment, records are maintained for multiple data stores that associate primary key indicators and time intervals pertaining to data items with distinct data stores. When a request pertaining to at least one data item is received, a primary key indicator and the time of this data item are determined. Further, the records maintained for the multiple data stores are searched using the primary key indicator and the time of the data item to find one or more data stores for the data item.