Applying the Sliding Window Technique

In this section:

To apply the sliding window technique correctly, you need to understand the difference between a date format (formerly called a smart date) and a legacy date:

For details on date fields, see the Describing Data manual.

When to Supply Settings for DEFCENT and YRTHRESH

Reference:

The rest of this topic refers simply to DEFCENT when either DEFCENT or FDEFCENT applies, and to YRTHRESH when either YRTHRESH or FYRTHRESH applies.

Supply settings for DEFCENT and YRTHRESH in the following cases:

Follow these rules when implementing the sliding window technique:

Finally, keep in mind that the sliding window technique does not change the way existing data is stored. Rather, it accurately interprets data during application processing.

Reference: Restrictions With MODIFY

The following results occur when you use the sliding window technique with a MODIFY request or FOCCOMP procedure:

  • A MODIFY request compiled prior to Version 7.0 Release 6, when run with global SET DEFCENT and SET YRTHRESH settings, or with file-level or field-level settings, yields a FOC1886 error message. You must recompile the MODIFY request.
  • A MODIFY request compiled in Version 7.0 Release 6, when run with global SET DEFCENT and SET YRTHRESH settings, or with file-level or field-level settings, yields a FOC1885 warning message.
  • A FOCCOMP procedure, compiled with global SET DEFCENT and SET YRTHRESH settings, and run in releases prior to Version 7.0 Release 6, yields a FOC548 invalid version message. You must recompile the MODIFY request.
  • A FOCCOMP procedure that contains DEFCENT/YRTHRESH or FDEFCENT/FYRTHRESH attributes in the associated Master File, and run in releases prior to Version 7.0 Release 6, yields a FOC306 description error message.

Date Validation

Date formats are validated on input. For example, 11/99/1999 is rejected as input to a date field formatted as MDYY, because 99 is not a valid day. Information Builders generates an error message.

Legacy dates are not validated. The date 11991999, described with the format A8MDYY, is accepted, even though it, too, contains the invalid day 99.


Information Builders