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.