Extending size of VSAM Shared DASD with Telon

Products

• Telon Application Generator

Issue/Introduction

The problem is using SHAREOPT(4,4), extending the VSAM size will fail because of DISP=SHR. This is from the VSAM documentation. 

Environment

Telon® Application Generator

Cause

It has to do with the buffers and control area splits.

Resolution

With SHAREOPT(4,3) it doesn't have this problem because of the CBUF which eliminates the restriction of control area splits.    

You need to modify all your JCL to include the DD parameter RLS=CR      
                                                                          
"You can install the TDF database on SMS-managed DASD, and activate RLS by adding the RLS parameter to each of the DD statements of the data sets that make up the TDF database. If this option is used, the RLS parameter must be either CR or CRE."      

The parameters are shop specific, with regards to response time, and data integrity.                                                     
                                                                         
RLS=CR, Consistent Read; the application will put a share lock on        
        the record while reading and will not read records that are held 
        for update by another user.                                      
                                                                         
RLS=CRE, Consistent Read Explicit; the application will hold a record it 
         it is reading until is issues a commit point. CRE only works with
         applications that log updates and use commits to manage         
         transaction back out.     

Sample JCL                                     
                                               
//DDNAME    DD  DSN=dataset.name, DISP=SHR,RLS=CR