Record trimming method, apparatus, and system to improve processing in a sort utility

• US 20040193618A1
• Filed: 03/28/2003
• Published: 09/30/2004
• Est. Priority Date: 03/28/2003
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Yaeger, Frank L.
• Granted Patent: US 7,117,209 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G06F 16/24553 of query operations
• CPC Class Codes: Y10S 707/99937 Sorting
• CPC Class Codes: Y10S 707/99945 Object-oriented database structure processing

Abstract

Control statements related to record input, output, filtering, and formatting in a data processing system are scanned by a parser to find one or more trimming control parameters referenced in the control statements. A record trimming module scans selected data records backwards beginning at the end of the record. A record length associated with a data record is decremented as trailing values that match a value specified in the trimming control parameters are trimmed from the processed records. Processed data records are output to a specified file. The present invention increases the efficiency of processing data records within data processing applications such as pipelined sort utilities.

Claims

1. A method for trimming data elements matching a specified value from data records, the method comprising:

scanning control statements associated with a set of data records;

finding at least one trimming control parameter within the control statements;

scanning from the end of a data record until a data element does not match a value specified by the at least one trimming control parameter; and

modifying a record length associated with the data record.

2. The method of claim 1, wherein modifying the record length associated with the record comprises decrementing the record length.

3. The method of claim 1, wherein modifying the record length associated with the record comprises decrementing a value with a register.

4. The method of claim 1, further comprising determining the length of the record.

5. The method of claim 1, further comprising storing the at least one trimming control parameter in readily accessible locations.

6. The method of claim 1, further comprising copying and storing the record within at least one register.

7. An apparatus for trimming specified trailing values from a record associated with a set of data records, the apparatus comprising:

means for scanning control statements associated with a set of data records;

means for finding at least one trimming control parameter within the control statements; and

means for scanning backwards from the end of the record until a current value does not match a value specified by the at least one trimming control parameter.

8. The apparatus of claim 7, further comprising means for storing the at least one trimming control parameter in readily accessible locations.

9. The apparatus of claim 7, further comprising means for determining the length of the record.

10. The apparatus of claim 7, further comprising means for copying and storing the record within at least one register.

11. A system for processing data records, the system comprising:

a computer configured to process data records; and

a utility for processing data records, the utility comprising a parser configured to scan control statements and find at least one trimming control parameter referenced in the control statements, and a record trimming module configured to eliminate trailing values within data records.

13. The system of claim 13, wherein the record trimming module is further configured to scan a data record backwards.

12. The system of claim 13, wherein the record trimming module is further configured to determine the length of data records.

14. The system of claim 13, wherein the record trimming module is further configured to remove values matching a value specified in the at least one trimming control parameter.

15. The system of claim 13, wherein the record trimming module is further configured to modify a record length.

16. The system of claim 13, wherein the record trimming module is further configured to decrement the record length.

17. The system of claim 13, wherein the record trimming module is further configured to scan the data record backwards until a value does not match a value specified in the at least one trimming control parameter.

18. A method for trimming data elements matching a specified value from data records, the method comprising:

scanning control statements associated with a set of data records;

finding at least one trimming control parameter within the control statements;

scanning from the end of a data record until a data element does not match a value specified by the at least one trimming control parameter; and

modifying a record length associated with the data record.

20. The computer readable storage medium of claim 18, wherein the code is configured to modify the record length associated with the record by decrementing the record length.

19. A computer readable storage medium comprising computer readable program code for trimming trailing values from data records, the program code configured to:

scan control statements associated with a set of data records;

find at least one trimming control parameter referenced in the control statements;

determine the length of a data record;

scan the data record backwards starting at the last data element;

eliminate each data element having a value that matches a value specified by the at least one trimming control parameter; and

modify a record length associated with the data record.

21. A method for trimming data elements matching a specified value from data records, the method comprising:

scanning control statements associated with a set of data records;

scanning from the end of a data record until a data element does not match a value specified by a trimming control parameter; and

modifying a record length associated with the data record; and

determining the length of the record.