Copyright © TIBCO Software Inc. All Rights Reserved
Copyright © TIBCO Software Inc. All Rights Reserved


Chapter 8 Managing VSAM Data Definitions : Task B: Identify the Data

Task B: Identify the Data
You use this step to specify the location of the data you want to access and the type of data set.
Data Identification Segment
The following example illustrates the fields used to identify the data:

 
File : USR40.EMPLOYEE.VSAM
DDname: Read Only: Y Load: N Data Set Type: KSDS
Ignore:
Server ID:

 
File Field
The File field contains the name of the VSAM file that holds the data you want to access. The maximum record size is 31,744 bytes. The record length must be equal to or greater than the total length of the table fields.
If you are accessing multiple VSAM files with the same record layout, you can omit both the File name and DD name and instead specify the data set name as the first data parameter (it must have syntax C and a length of 44).
Under CICS, define the VSAM data set in the File Control Table (FCT) and in the JCL. You must provide the key length of the VSAM records in the File Control Table.
DDname Field
The DDname field contains the name of the JCL DD statement defining the file containing the data you want to access.
Using a DDname
If you use a DDname, note the following:
It must already be allocated by the TIBCO Object Service Broker Execution Environment, using a JCL DD statement or the TSO ALLOCATE command.
Read Only Field
The Read Only field contains a logical value that determines whether the data in the table can be modified. If Read Only=Y, the data can only be read. If Read Only=N, the data can be both read and modified.
Field overlaps are allowed only for Read Only tables. If your definition has overlapping fields when the Read Only flag is N, you are not allowed to save the definition.
Load Field
The Load field contains a logical value to signal whether the VSAM table is to be initialized with data. The default is N. Type Y if you are initializing the data. You can change the value in this field to N after loading the initial data. You cannot read or change the loaded data; however, records are inserted into KSDS and RRDS types more efficiently.
Data Set Type Field
The Data Set Type field contains a 1 to 4 byte string identifying the type of VSAM data set.
Ignore Field
The Ignore field contains a value to identify the records to ignore in a KSDS data set. The Ignore field is defined and used as follows:
If the key field is a string containing any unprintable characters, you can specify a hexadecimal string using X’ as a prefix and a single quotation mark (‘) as a suffix. For example:
X’hhh…hh’
Processing Records
Records are processed as follows:
If you request a sequence of records (a FORALL statement) or a non-specific record (a GET statement without a WHERE clause) and the ignore value matches the start of a record’s key, that record is ignored and the next one is obtained.
If you request a specific record (a GET statement with a WHERE clause) or perform update operations, no records are ignored.
Server ID Field
The Server ID field points to the gateway that is to be used if the table is to be accessed remotely via the Service Gateway for Files (z/OS). This is an optional specification. The value in this field is determined from the SERVERID Execution Environment parameter.
Refer to Monitoring of Service Gateway for Files for details on ServerID and Service Gateway for Files.
See Also
TIBCO Object Service Broker Parameters for information about the SERVERVID parameter.

Copyright © TIBCO Software Inc. All Rights Reserved
Copyright © TIBCO Software Inc. All Rights Reserved