Rational Developer for System z, Version 7.6

-DC Lines in a Database block

The -DC Lines tab is dedicated to the description of the CODASYL, DMSII and TANDEM Batabase blocks. You can declare the areas, call the records and distribute them within the AREAS, call the SETS and describes them (code, clear name, parent and child Segments).

This description is common to the following Block types:

-DC Lines definition

Network record type
Select in the dropdown list a type pf line among the authorized values:
Value Description
* Continuation of a set. For a set with multiple members, the first 'MEMBER' Segment is indicated on an 'S' line type and the other ones on the '*' line types.
S Set (default option).
A Area,

TANDEM Database

R Record.
Database object name
You enter in this field the code which corresponds to the selected description line type.
  • Type 'S': Set code, with 5 characters
  • Type 'A': Area code, with 5 characters
  • Type 'R': Code of area to which the record belongs.
Segment
This field cannot be used if the type of line is 'A' (Area).
  • CODASYL database:
    • This field cannot be used if the type of line is 'A'.
    • If the type is 'R', you enter here the code of the Segment.
    • If the type is 'S', you indicate the parent Segment code.
  • TANDEM database:

    You enter in this field the Segment code which corresponds to the called record. When the Database Block is generated, this code is displayed after the 'RECORD' clause.

    To enter or modify the contents of this field, click on Change and then in the list which displays in a dialog box, select a Segment.

Child Segment
This field can be used with a 'S'-type line only. Select here the child Segment code (MEMBER) via the Change as for the Segment code.
From Segment
This field is active only for a 'R'-type line (Record). In this field, you must enter the name of the physical file (FILE NAME), which supports the data. When the Database Block is generated, this name is displayed after the 'FILE IS' clause.
Method name
SCHEMA:

This field can be used with a 'S'-type line only. You enter here the Relationship code from which the set is derived. VA Pac will automatically create a cross-reference for these relationships.

SUB-SCHEMA:

Only used for IDMS ('D3', 'D4' types), DM4 ('M3' type) and DMS ('S3' type) sub-schemas.

On a 'R'-type line, you can change the description of the selected record.

Number of Occurences of sets
This field can be used with a 'S'-type line only. You enter in this field the average number of occurrences of the child Segment that are linked to an occurrence of the father Segment. This number is used for the activity calculation.
Area name, Set name or comment
CODASYL database:

Depending on the value of the 'Type' of line selected, you enter in this field:

  • the name of the Set ('S'-type),
  • the name of the Area ('A'-type),
  • a comment ('R'-type).
For an IDMS (D4) or DMS (S3) subschema:

You can select a sub-schema at the Block description level. To do so, with an 'R'-type lines, enter SS=n (with 'n' being the sub-schema number according to the VA Pac definition). For an IDS2 (I3) sub-schema, it is possible to call an object (area, record, set) without re-describing it, by specifying: INCLUSION.

For an IDMS sub-schema, it is possible to select a sub-schema at the block description level. To do so, with lines of "Type" 'R', enter SS=n (with 'n' being the sub-schema number ac- cording to the PACBASE definition). (See the description line of a record).
Example: A LIN : T AREA RECORD SOURCE OCC AREA NAME SET PARENT/CHILD METHOD AID SET SET NAME
340 R AREA1 FF10 SS=3
TANDEM database:

You enter in this field the name of the physical file which supports the data. When the Database Block is generated, this name appears after the 'FILE IS' clause.

-GG Lines

The -GG lines section displays when you enter or click on a -DC description line. In this section, you can enter information to complete the description line.

This section consists of a table in which you can modify the information contained in the Block Description lines before they are generated. Depending on the type of description line, the System automatically displays lines, in order to guide you when you enter the Block's physical information. These lines are identified by 'VIRT' or 'GUID' in the last field of the table. Collectively, these lines are called 'virtual' lines. The lines identified by 'VIRT' are generated. You can create new lines and override the 'virtual' lines generated by the DBD function if you want to modify them. A 'G' entered in the Type field means that the lines are to be taken into account at generation time.

TYPE
  • To modify the description of -DC lines, you can use the following lines:
    • *: to generate comment lines,
    • G : to override the automatically generated elements.
    • V: to indicate data before the dataset.
    • P : to type lines before the dataset description (POPULATION for instance).
    • Z : to enter clauses located after the dataset description (Physical options for instance).
DESCRIPTION
You can use the virtual lines to specify the physical characteristics of the areas and sets (DMCL), including the information related to sort keys and insertion modes.
  • You can modify a virtual line as follows:
    G RECORD < RECORD NAME > .
    G RECORD SS00 .
    The lines that you want to have included in the generation must be marked by a'G'-type line.
  • You can override a Data element:
    • You must create line numbers included inside the ″Begining of insertion″ and ″End of insertion″ boundaries.
    • To ″override″ a Data Element, you must specify <DELCO> on the first line, and the new description on the following lines.
    • If you do not want the new Data Element to appear, do not create any line after this first line. You must enter at least six characters between the two delimiters.
      Example:
      G RECORD < RECORD NAME > . 
      G FILE IS < FILE NAME > .
      G KEY-SEQUENCED .
      G ---> ELEMENT INSERTION BEGINING <---
      G<NUCLIE>
      G 10 NUCLIE PICTURE X(8).
      G ---> ELEMENT INSERTIOM END <--
      G KEY IS < FIELD NAME > .

For more details on the generation lines, see the explanations about generation lines in Creating -GG lines associated with this page.


Terms of use | Feedback

This information center is powered by Eclipse technology. (http://www.eclipse.org)