DATAAREA
What is Data
Area?
Data area is used to store
constant values, which can be retrieved by many users. Is an object of type
*DTAARA which is located in auxiliary storage. Data area may be created by
CRTDTAARA command and it is viewed by DSPDTAARA command, their values updated
by CHGDTAARA command. There are three data types in data area is *DEC maximum
24 digit with maximum 9 digit of decimal places and *CHAR type has maximum 2000
character length and *LGL may contain 1 or 0 including on/off responsibility.
RPG operation for Data Area processing:
IN retrieve data from a data area
OUT write data to a data area
DEFN define a data area
LDA, GDA
and PIP.
LDA Local Data Area is created for
each job in the system, including auto start jobs; jobs started on the system
by reader and subsystem monitor jobs.
The system creates a local data
area, which is initially filled with blanks, with a length of 1024 and type
*CHAR. When you submit a job using SBMJOB command, the value of the submitting
job’s local area is copied into the submitted job’s local data area. You can
refer your job’s local data area by specifying *LDA for the DTAARA keyword on
the CHGDTAARA, RTVDTAARA and DSPDTAARA commands or *LDA for the sub string
built-in function (%SST)
The local
data area can’t be referred to from any other object.
You can’t
create, delete or allocate the local data area.
No
library is associated with the local data area.
GDA Group Data Area will be created
by the system when an interactive job becomes a group job. Only one group data
area can exist for a group. The group data area can be deleted when the last
job in the group is ended or when the job is no longer part of the group job.
The group data area which is initially filled with blanks has a length of 512
and type *char.
You can’t use the group data area
as a substitute for a character variable on the sub string built-in function.
A GDA
can’t be referred by jobs outside the group.
You can’t
create, delete and or allocate a GDA
No
library is associated with GDA
PIP (Data Area)
Program Initialization Parameter (Data Area) is created for each pre
start job when the job is started. The object sub-type is of the PDA is
different then regular data area. The PIP can only be referred to by the
special name *PDA and the size is 2000.
RPG opcodes
associated with data areas?
IN, OUT, UNLCK
and DEFN.
Data areas and its types.
Data area is an
area in main memory. The types are General DA, Local DA, Group DA and PIP DA.
DAs are used to hold some data.
Referring the General DA in RPG and CL?
In RPG, *DTAARA,
DEFN, *LOCK, *UNLOCK, IN and OUT commands are used.
In CL, CRTDTAARA, CHGDTAARA,
RMVDTAARA, DSPDTAARA, RTVDTAARA commands are used.
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