DASD Retrieval Via Outboard Multilevel Index Scan
Original Publication Date: 1979-Jun-01
Included in the Prior Art Database: 2005-Feb-20
It is desirable and economically justifiable for a microprocessor-based direct-access storage device (DASD) control unit (CU), implementing a fixed-block architecture, to be used for retrieving data in a data set by some random means via its associated keys grouped in a separate data set. The required buffer for key searching, with its capacity equal to the size of a data block, a basic DASD data transfer unit, normally exists in the CU for matching the data rate of a low- cost channel to that of a high speed DASD (Fig. 1).