The -DC Lines tab is dedicated to
the description of the CODASYL, DMSII, and TANDEM Database Blocks.
You can declare the areas, call the records, and distribute them within
the AREAS, call the SETS and describe them (name, label, parent, and
child Segments).
This description is common to the following Block types:
-DC Lines definition
- Network record type
- Select a type of line among the authorized values:
Table 1. Type of lineValue |
Description |
* |
Continuation of a set. For a set with multiple
members, the first member Segment is indicated on an S-type
line and the other Segments on *-type lines.
|
S |
Set (default option). |
A |
Area, TANDEM database
|
R |
Record. |
- Database object name
- In this field, you enter the code which corresponds to the selected
description line type.
- Type S: Set code, on five characters
- Type A: Area code, on five characters
- Type R: Code of the area to which the record
belongs.
- Segment
- This field cannot be used if the type of line is A (Area).
Select the parent Segment or record depending on the type of description
line selected.
- CODASYL database:
- If the type is R, you select the record
code.
- If the type is S, you indicate the parent
Segment code.
- TANDEM database:
You enter the Segment code which corresponds
to the called record. When the Database Block is generated, this code
is displayed after the RECORD clause.
To modify
the contents of this field, click Change. Then
select a Segment. If the list is large, you can reduce it by entering
a string that is used as a filter (the filtering is performed on the
code or on the label of the instance).
- Child Segment
- This field can be used with an S-type
line only. Select the child Segment code (member) by clicking the Change button,
as for the Segment code.
- From Segment
- This field is active only for an 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 an S-type
line only.
- Subschema:
Only used for IDMS (D3, D4 types), DM4 (M3 type)
and DMS (S3 type) subschemas.
On an R-type
line, you can change the description of the selected record.
- Number of Occurrences of sets
- This field can be used with an S-type line
only. You enter the average number of occurrences of the child Segment
that are linked to an occurrence of the parent 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:
- The name of the Set (S-type line),
- The name of the Area (A-type line),
- A comment (R-type line).
- For an IDMS (D4) or DMS (S3) subschema:
You can select a subschema
at the Block description level. To do so, on R-type
lines, enter SS=n (with n being
the subschema number according to the definition). For an IDS2 (I3)
subschema, it is possible to call an object (area, record, set) without
redescribing it, by specifying: INCLUSION.
- TANDEM database:
You enter the name of the physical file which
supports the data. When the Database Block is generated, this name
is displayed after the FILE IS clause.
- -G Lines
- This button can be used to access the -G Lines wizard
and create -GG lines associated with the description line to specify
generation elements.