Your program uses IDENTIFY to select the data-in-virtual object
that you want to process. IDENTIFY has four parameters: ID, TYPE,
DDNAME, and STOKEN.
The following examples show two ways to code the IDENTIFY service:
- Hiperspace object:
DIV IDENTIFY,ID=DIVOBJID,TYPE=HS,STOKEN=HSSTOK
- Data set object:
DIV IDENTIFY,ID=DIVOBJID,TYPE=DA,DDNAME=DDAREA
- ID:
- The ID parameter specifies the address where the IDENTIFY service
returns a unique eight-byte name that connects a particular user with
a particular object. This name is an output value from IDENTIFY,
and it is also a required input value to all other services.
Simultaneous
requests for different processing activities against the same data-in-virtual
object can originate from different tasks or from different routines
within the same task or the same routine. Each task or routine requesting
processing activity against the object must first invoke the identify
service. To correlate the various DIV macro invocations and processing
activities, the eight-byte IDs generated by IDENTIFY are sufficiently
unique to reflect the individuality of the IDENTIFY request, yet they
all reflect the same data-in-virtual object.
- TYPE:
- The TYPE parameter indicates the type of data-in-virtual object,
either a linear data set (TYPE=DA) or a hiperspace (TYPE=HS). DIV does not support VSAM extended format linear data
sets for use as a DIV object for which the size is greater than 4GB.
- DDNAME:
- When you specify TYPE=DA for a data set object, you must specify
DDNAME to identify your data-in-virtual object. If you specify TYPE=HS
with IDENTIFY, do not specify DDNAME. (Specify STOKEN instead.) Do not specify a DDNAME that corresponds to a VSAM extended
format linear data set for which the size is greater than 4GB, because
DIV does not support them for use as a DIV object.
- STOKEN:
- When you specify TYPE=HS for a hiperspace object, you must specify
STOKEN to identify that hiperspace. The STOKEN must be addressable
in your primary address space. The hiperspace must be a non-shared
standard hiperspace and must be owned by the task issuing the IDENTIFY.
The system does not verify the STOKEN until your application uses
the associated ID to access the object.