Record Sampling panel

The Record Sampling panel is used to specify a repeating sample pattern that will limit the number of records presented in an editor session.

In a repeating sample:

  1. The Start position is set first, and always applies to the physical records, before any template processing is applied.
  2. If a template is in use, the template selection criteria then filters the data set and the Initial skip field is used to determine the number of selected records to skip.
  3. Records are then read from the data set and template processing (if a template is used) occurs on them. Records are included in the Edit session until the number of selected records (if not using a template, the number of physical records) matches the Include selected records field value.
  4. After the above number of selected records have been included, the number of selected records in this field will then be skipped. (If not using a template this is physical records) They are not presented in any form in the editor session.
  5. Steps 3 and 4 are then repeated until either the end of the data set, or the total number of selected records has been included as specified (in the Total selected record limit field) (if using a template), or the total number of physical records as specified has been read, or Z Data Tools can contain no more records in virtual storage.

Panel and field definitions

Figure 1. Record Sampling panel, when no template is used
  Process   Options   Help
 ──────────────────────────────────────────────────────────────────────────────
 Z Data Tools                   Record Sampling

 Positioning:
    Starting position . . . .          
    Start position type . . .   1. Key
                                2. RBA
                                3. Record number
                                4. Formatted key
 Sampling:
    Include physical records           
       Skip physical records           
 Total physical record limit           

 Command ===>                                                                  
  F1=Help      F2=Split     F3=Exit      F4=CRetriev  F7=Backward  F8=Forward
  F9=Swap     F10=Actions  F12=Cancel                                           
Starting position
This represents the physical record number to set the starting point of the editor session. The default is record 1, meaning the top of the data set. A value entered in the Start position field on the View Entry or Edit Entry panel, is carried through to this panel when it is opened.
Start position type
Determines how Z Data Tools interprets the value provided in the Starting position field. If the Start position type is not specified, Z Data Tools assumes that the value is a record number.
Note: The available selections below are changed so that only those valid for the selected file type appear.
1. KEY
Only valid when the data set is a VSAM KSDS, VSAM AIX®, or VSAM PATH.
2. RBA
Only valid when the data set is a VSAM KSDS, VSAM AIX, or VSAM ESDS.
3. Record Number
Default. Valid for any type of supported data set.
4. Formatted key
Only valid when the dataset is a VSAM KSDS, VSAM AIX, or VSAM PATH and when a template is provided. This displays the formatted Key Positioning panel.
Note: For templates with more than one layout, a 01 selection list is displayed first.
Include physical records
This represents the number of physical records that is to be included in a repeating sample from the data set. When this field is used, both this field and the Skip physical records fields must have nonzero values.
Skip physical records
This represents the number of physical records that is to be skipped in a repeating sample from the data set. The Include physical records field must have a nonzero value for this field to have any meaning.
Total physical record limit
This represents the total number of physical records that wil be read from the data set. If the Include physical records and Skip physical records fields are used, only the included records are counted in this total. The editor session will contain records from the data set up to the end of the data set, or the total number of physical records as specified in this field has been read, or Z Data Tools can contain no more records in virtual storage, whichever occurs first.
Figure 2. Record Sampling panel, when a template is used
  Process   Options   Help
 ──────────────────────────────────────────────────────────────────────────────
 Z Data Tools                   Record Sampling

 Positioning:
    Starting position . . . .          
    Start position type . . .   1. Key
                                2. RBA
                                3. Record number
 Sampling:
    Initial skip  . . . . . .          
    Include selected records           
       Skip selected records           
 Total selected record limit           

 Command ===>                                                                  
  F1=Help      F2=Split     F3=Exit      F4=CRetriev  F7=Backward  F8=Forward
  F9=Swap     F10=Actions  F12=Cancel                                           
Initial skip
This field is only available when processing with a template. This represents the number of records regarded as selected by the template processing that will initially be skipped. These records are not presented in any form in the editor session.
Include selected records
This represents the number of selected records that are included in a repeating sample from the data set. When this field is used, both this field and the Skip selected records fields must have nonzero values.
Skip selected records
This represents the number of selected records that are skipped in a repeating sample from the data set. The Include selected records field must have a nonzero value for this field to have any meaning.

Related tasks and examples