The Content Addressable File Store (CAFS)[1] was a hardware device developed by International Computers Limited (ICL) that provided a disk storage with built-in search capability.
[2][3] Development of CAFS started in ICL's Research and Advanced Development Centre under Gordon Scarrott in the late 1960s following research by George Coulouris and John Evans who had completed a field study at Imperial College and Queen Mary College on database systems and applications [3].
Their study had revealed the potential for substantial performance improvements in large-scale database applications by the inclusion of search logic in the disk controller.
By this stage, to reduce costs and to take advantage of increased hardware speeds, the search logic was incorporated into the disk controller.
Managing data integrity in a concurrent environment also required close attention, since a CAFS search would execute without any knowledge of locks and caches maintained by the database software.