Method and system for data search in a data processing system

• US 5,721,898 A
• Filed: 09/02/1992
• Issued: 02/24/1998
• Est. Priority Date: 09/02/1992
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Benhase, Michael Thomas, Candelaria, Susan Kay, Blount, Lawrence Carter, Beardsley, Brent Cameron, Hyde, Joseph Smith
• Primary Examiner(s): Chan, Eddie P.
• Assistant Examiner(s): Nguyen, Hiep T.
• Application Number:
  US07/939,241
• Time in Patent Office: 2,001 Days
• Field of Search: 364/200 MS File, 364/900 MS File, 395/400, 395/425, 395/600, 395/603, 395/445, 395/440, 395/439
• US Class Current: 1/1
• CPC Class Codes: G06F 2003/0697 device management, e.g. handlers, drivers, I/O schedulers
• CPC Class Codes: G06F 3/0601 Interfaces specially adapted for storage systems
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0637 Permissions
• CPC Class Codes: G06F 3/0683 Plurality of storage devices

Abstract

A method and system for enhancing the efficiency of communication between one or more host computers and a storage system controller during a data search within either the associated storage systems or within the storage system controller itself. A storage system controller, coupled to one or more host computers via multiple communication channels, is utilized to control access to one or more direct access storage devices. A host computer authorizes the storage system controller to search within a range of data locations within the storage system, sets an initial location from which the data search will begin, and specifies a key field argument to search for. The host computer then permits the storage system controller to independently search the authorized range of data locations within the storage system or within cache memory within the storage system controller. The storage system controller examines multiple records within the authorized range of data locations to locate a desired record associated with the key field argument and presents a status report to the host computer only after the desired record is located or the entire range of data is searched and the desired record was not located. Allowing the storage system controller to independently search records and report status only after completion of an attempt to find a desired record within an authorized range of records minimizes communication overhead. Reducing the number of status reports presented over the communication channel enhances communication efficiency.

Claims

1. A method for enhancing the efficiency of communication between one or more host computers and a storage system controller during a data search within one or more storage systems associated with said storage system controller, the method comprising the steps of:

authorizing a data search by transmitting a range of data locations from one of said host computers to said storage system controller, wherein said range of data locations includes locations of multiple records within said one or more storage systems;

setting an initial location from which said data search will begin;

specifying a key field argument;

permitting said storage system controller to search said range of data locations within said one or more storage systems;

examining key fields in multiple records within said range of data locations within said storage system to locate a record associated with said key field argument; and

transmitting a report from said storage system controller to said one of said host computers only in response to a location of a record within said range of data locations or a failure to locate said record associated with said key field argument, wherein communication between said one or more host computers and said storage system controller is minimized.

2. The method for enhancing the efficiency of communication between one or more host computers and a storage system controller according to claim 1 wherein said storage system controller includes a cache memory area containing stored records, further comprising the steps of:

determining whether said stored records stored in said cache memory storage area within said storage system controller are within said authorized range of data locations;

examining multiple records stored within said cache memory storage area to locate a record associated with said key field argument; and

transmitting a report from said storage system controller to said host computer only in response to allocation of a record within said range of data locations within said cache memory storage area, wherein communication between one or more host computers and said storage system controller is minimized.

3. The method for enhancing the efficiency of communication between one or more host computers and a storage system controller according to claim 2 wherein said storage system controller includes a cache memory area containing stored records, and wherein the step of examining key fields in multiple records within said range of data locations further comprises the steps of:

examining key fields in multiple records within said range of data locations within said one or more storage systems to locate a record associated with said key field argument in response to a failure to find a record associated with said key field argument located in said cache memory area within said storage system controller; and

transmitting a report from said storage system controller to said one of said host computers in response to a location of a record associated with said key field argument within said range of data locations, or a failure to locate said record associated with said key field argument, wherein communication between said one or more host computers and said storage system controller is minimized.

4. A method for enhancing the efficiency of communication between one or more host computers and a storage system controller according to claim 3 wherein the step of examining key fields in multiple records further comprises the step of:

comparing the length of said key field argument with the length of a current key field arguments for each of said multiple records within said authorized range of data locations within said storage system.

5. A system for enhancing the efficiency of communication between one or more host computers and a storage system controller during a data search within one or more storage systems associated with said storage system controller, said system comprising:

control means for authorizing a data search by transmitting a range of data locations from one of said host computers to said storage system controller, wherein said range of data locations includes locations of multiple records within said storage system, and for setting an initial location from which said data search will begin, and for specifying a key field argument;

a storage system controller for searching said range of data locations within said storage system;

examination means within said storage system controller for examining key fields in multiple records within said range of data locations within said storage system to locate a record associated with said key field argument; and

means for transmitting a report from said storage system controller to said one of said host computers only in response to a location of a record within said range of data locations or a failure to locate said record associated with said key field argument, wherein communication between said one or more host computers and said storage system controller is minimized.

6. The system for enhancing the efficiency of communication between one or more host computers and a storage system controller according to claim 5 wherein said storage system controller includes a cache memory area therein, and wherein said examining means includes means for examining key fields in multiple records within said cache memory area.

7. The system for enhancing the efficiency of communication between one or more host computers and a storage system controller according to claim 5 wherein said means for transmitting a report from said storage system controller to said one of said host computers includes a serial communications link between said storage system controller and said one or more host computers.

8. The system for enhancing the efficiency of communication between one or more host computers and a storage system controller according to claim 7 wherein said serial communications link between said storage system controller and said one or more host computers is an optical serial communications link.