BUFNO= Data Set Option

Specifies the number of buffers to be allocated for processing a SAS data set.

Valid in:	DATA and PROC steps
Category:	Data Set Control
Supports:	SAS data set

Syntax

Details

Comparisons

Syntax

BUFNO=n | nK | hexX | MIN | MAX

Syntax Description

n | nK: specifies the number of buffers in multiples of 1 (bytes); 1,024 (kilobytes). For example, a value of 8 specifies 8 buffers, and a value of 1k specifies 1024 buffers.

hex: specifies the number of buffers as a hexadecimal value. You must specify the value beginning with a number (0-9), followed by an X. For example, the value 2dx sets the number of buffers to 45 buffers.

MIN: sets the minimum number of buffers to 0, which causes SAS to use the minimum optimal value for the operating environment. This is the default.

MAX: sets the number of buffers to the maximum possible number in your operating environment, up to the largest four-byte, signed integer, which is 2³¹-1, or approximately 2 billion.

Details

The buffer number is not a permanent attribute of the data set; it is valid only for the current SAS session or job.

BUFNO= applies to a SAS data set that is opened for input, output, or update.

A larger number of buffers can speed up execution time by limiting the number of input and output (I/O) operations that are required for a particular SAS data set. However, the improvement in execution time comes at the expense of increased memory consumption.

To reduce I/O operations on a small data set as well as speed execution time, allocate one buffer for each page of data to be processed. This technique is most effective if you read the same rows several times during processing.

Comparisons

If the BUFNO= data set option is not specified, the value of the BUFNO= system option is used. If both are specified in the same SAS session, the value specified for the BUFNO= data set option overrides the value specified for the BUFNO= system option.