Limit on SYSIDMS parameter FILE_BUF

Products

• IDMS
• IDMS - Database

Issue/Introduction

Is there a limit to the number of FILE_BUF parameters that can be specified in a SYSIDMS for a local batch job?

Environment

Release: All supported releases.

Resolution

Yes. There is a limit of 100 FILE_BUF parameters. This should not be a problem unless there are more than 100 buffer definitions in the DMCL used by the local batch job.

In most cases, there will be multiple files assigned to the same buffer. A FILE_BUF parameter for any of the files that share the buffer will add the specified pages to the buffer when that buffer is allocated. These pages are not restricted to the named file, they simply add to the assigned buffer. There is no need to code a FILE_BUF for each file assigned to a buffer. In fact this will add the pages specified for each FILE_BUF parameter to the shared buffer.

For example, if files 1 through 6 are assigned to the same buffer, and SYSIDMS has the following:

FILE_BUF=FILE01=100
FILE_BUF=FILE02=100
FILE_BUF=FILE03=100
FILE_BUF=FILE04=100
FILE_BUF=FILE05=100
FILE_BUF=FILE06=100

then 600 pages will be added to the buffer.