Table of Contents

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  1. Preface
  2. Introduction to PowerExchange
  3. DBMOVER Configuration File
  4. Netport Jobs
  5. PowerExchange Message Logs and Destination Overrides
  6. SMF Statistics Logging and Reporting
  7. PowerExchange Security
  8. Secure Sockets Layer Support
  9. PowerExchange Alternative Network Security
  10. PowerExchange Nonrelational SQL
  11. PowerExchange Globalization
  12. Using the PowerExchange ODBC Drivers
  13. PowerExchange Datatypes and Conversion Matrix
  14. Appendix A: DTL__CAPXTIMESTAMP Time Stamps
  15. Appendix B: PowerExchange Glossary

VSAM Statement

VSAM Statement

The VSAM statement specifies the number of buffers that PowerExchange uses for data and index control intervals when processing VSAM data sets.
For more information about optimizing performance and system-managed buffering, see the DFSMS documentation.
z/OS
VSAM data sets
No
VSAM=([BUFNI=
index_buffers
] [,BUFND=
data_buffers
] )
BUFNI=
index_buffers
Optional. Number of I/O buffers that PowerExchange uses for VSAM index control intervals. A buffer is the size of a control interval in the index.
For the
index_buffers
variable, enter one of the following values:
  • 0, to use the operating system default
  • A number from 1 through 255
BUFND=
data_buffers
Optional. Number of I/O buffers that PowerExchange uses for VSAM data control intervals. A buffer is the size of a control interval in the data component.
For the
data_buffers
variable, enter one of the following values:
  • 0, to use the operating system default
  • A number from 2 through 255
You cannot specify 1 for BUFND.
  • Additional index buffers improve performance by providing for the residency of some or all of the high-level index. Additional buffers minimize the number of high-level index records retrieved from DASD for key-direct processing.
    The usual practice is to set the number of buffers that PowerExchange uses for data and index control intervals in data maps for individual bulk data movement operations rather than to use the global VSAM statement to set these values.
  • Additional data buffers benefit direct inserts or updates during control area splits and spanned record processing.
  • The maximum number of buffers allowed is 255, which represents 254 data buffers and one insert buffer.