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Extended Format and the DATACLAS enables SMB buffers, which takes precedence?

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Article ID: 201435

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Updated On:

Products

HYPER-BUF VSAM Buffer Optimizer

Issue/Introduction

If a KSDS VSAM file is allocated as Extended Format and the DATACLAS enables SMB buffers, which takes precedence?

I was told that “Generally speaking HB would only be used for non-EF (and non-IAM) files.  You may see messages about HB on EF files, however SMB jumped in after HB and ‘re- did’ the buffering at open. “  I would like to validate this is true.

 

Environment

Release : 11.5

Component : CA Hyper-Buf VSAM Buffer Optimizer

Resolution

HBUF will allow JCL overrides to take precedent.

HBUF does not examine SMS Data classes to make determinations,

If the entry is in the table it could interfere with the DATACLAS requirements.

It is recommended that you determine VSAM clusters that are SMS managed and buffered so you can EXCLUDE these from the  HBUFF Constraint table.

Since the HBUF intercepts would come in play before SMS, the situation experienced is a true function and could  be a concern. Not only in regard to overhead but also, SMS may have other specific requirements that is different than HBUF.