International Business Machines Corporation
Reading sequentially stored files based on read ahead groups

Abstract:

A plurality of files are stored on magnetic tape having at least one wrap for storing data sets. Each data set includes one or more records. A number of data sets that will remain in a buffer memory after performing a read ahead operation is determined. A number of records that are likely to remain in the buffer memory after performing a read ahead operation is determined. For each record likely to remain in the buffer memory after performing a read ahead operation, positions of the records on the magnetic tape are determined. Each file of the plurality of files are classified into one group of a plurality of groups based on a position of a record corresponding with each respective file and the number of records that are likely to remain in the buffer memory after performing a read ahead operation.