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Method of Outboard Data Search which Eliminates Unnecessary Data Transfer

IP.com Disclosure Number: IPCOM000113549D
Original Publication Date: 1994-Sep-01
Included in the Prior Art Database: 2005-Mar-27
Document File: 2 page(s) / 70K

Publishing Venue

IBM

Related People

Allen, VK: AUTHOR [+2]

Abstract

Described is a method of passing search arguments to a peripheral device (e.g., tape drive), having the peripheral device execute the search for data and report to the host processor when complete. The approach off-loads the search aspect of data processing from the host, thereby freeing up the host for more important/valuable processing.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 59% of the total text.

Method of Outboard Data Search which Eliminates Unnecessary Data
Transfer

      Described is a method of passing search arguments to a
peripheral device (e.g., tape drive), having the peripheral device
execute the search for data and report to the host processor when
complete.  The approach off-loads the search aspect of data
processing from the host, thereby freeing up the host for more
important/valuable processing.

Reference the Figure titled "Method of Outboard Data Search".

      The program running in the host processor is required to
determine which data on which media is to be searched for.  The host
is also responsible for mounting/making available for searching the
correct media or set of media.

      For instance, the program may want to determine how many of its
Accounts Receivable have a balance due of over $999.00.  To find this
out, the program would set up to search its account receivable files
which are on tape volumes "AR0027 thru AR0029".

      The Search command sent to the tape drive(s) would state that
for each block of data on each of these tapes, examine bytes at
displacement 100 thru 110 for a bit pattern greater than
'0000999.00'.  Furthermore, the Search command would instruct the
tape drive logic to track the number of blocks read, number of
positive comparison made and to return those blocks of data for which
positive comparison have been made.

From a peripheral hardware view, the execution of the Search command
is as foll...