Limiting Processing With FILEDF - GeoTAX_Premium - 7 - 7.7

GeoTAX Premium for Windows, UNIX/Linux, and z/OS

Product type
Software
Portfolio
Verify
Product family
Geo Addressing
Product
GeoTAX Premium
Version
7.7
Language
English
Product name
GeoTAX Premium
Title
GeoTAX Premium for Windows, UNIX/Linux, and z/OS
Copyright
2023
First publish date
1998
ft:lastEdition
2023-10-19
ft:lastPublication
2023-10-19T16:49:54.924301

There are three ways to limit input record processing:

  • Skip a portion of the file before you start processing.

  • Enter a cross-sectional sampling number to select a portion of the records, evenly spaced throughout the file.

  • Specify a maximum number of records; in this case, GeoTAX starts at the beginning of the file and processes each record, one after another, until it reaches the maximum.

Note: Specify the number of records you want to process with the input FILEDF parameter record. If you limit processing on an output FILEDF parameter record, GeoTAX processes all of your input records, but limits the number of records written to the output file.

Cross-Sectional Sampling

Cross-sectional sampling provides you with a way to process a sample (percentage) of your total input file to get a preview of the entire input file. This ensures your sampling is evenly distributed throughout the file.

You must specify your sampling percentage number as a 7-byte, decimal figure. Use the following steps to determine this number:

  1. Divide the number of records you want to process (for example, 2000) by the number of records in the file (in this case, 102986). The result is a decimal figure (.0194201153).

  2. Drop the decimal point from this figure (0194201153).

  3. Specify the first seven digits of this number in the input FILEDF parameter record (0194201).

Specifying FILEDF Exit Routines

You can specify and invoke two types of exit routines with the FILEDF parameter record.

  • Input exit routineGeoTAX calls this routine each time it is ready to read a record from your input data file. Instead of immediately reading the input record, GeoTAX first calls your exit routine, then waits for the exit routine to pass back a record before it resumes normal processing.

  • Output exit routineGeoTAX calls this routine each time it is ready to write a record to your output file. Before it writes the record to the output file, GeoTAX first passes the record to the output exit routine, then waits for the exit routine to complete processing and pass the record back to it for normal processing.

Your exit routine must contain four parameters in the linkage section at each I/O request.

  • PARM1 contains two components:

  • Bytes 1-8 contains the file name.

  • Byte 9 contains one of the following codes that indicate the type of processing the routine performs:

  • O - The routine opens the input or output file.

  • R - The routine reads an input file record.

  • W – The routine writes an output record.

  • C – The routine closes the input or output file.

  • PARM2 is an open/read indicator. This 5-digit parameter is packed into a 3-byte field (COBOL “PIC S9(5) COMP-3”). Your exit routine must initialize and increment this parameter if byte 9 of PARM1 is O or R. When byte 9 of PARM1 is R and the input exit routine reaches end-of-file, the routine sets this indicator to 0.

  • PARM3 contains the output record that GeoTAX passes to the exit routine each time it encounters an R or a W in byte 9 of PARM1. The length of this parameter is specified by the exit routine in PARM2 (maximum of 32,760).

  • PARM4 contains your 80-byte FILEDF parameter records.