System Options under OpenVMS

BUFNO= System Option: OpenVMS

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

Default:	1
Valid in:	configuration file, SAS invocation, OPTIONS statement, SAS System Options window, VMS_SAS_OPTIONS DCL symbol
Category:	Files: SAS Files
PROC OPTIONS GROUP=	SASFILES, PERFORMANCE
OpenVMS specifics:	Default value; valid values of n
See:	BUFNO= System Option in SAS Language Reference: Dictionary

Syntax
Details
See Also

Syntax

BUFNO= n | nK | nM | nG | hexX | MIN | MAX

n | nK | nM | nG: specifies the number of buffers to be allocated in multiples of 1 (bytes); 1,024 (kilobytes ); 1,048,576 (megabytes); or 1,073,741,824 (gigabytes). You can specify decimal values for the number of kilobytes, megabytes, or gigabytes. For example, a value of 8 specifies 8 buffers, a value of .782k specifies 801 buffers, and a value of 3m specifies 3,145,728 buffers.
hexX: specifies the number of buffers as a hexadecimal value. You must specify the value beginning with a number (0-9), followed by hexadecimal characters (0-9, A-F), and then followed by an X. For example, 2dx specifies 45 buffers.
MIN: sets the number of buffers to 0, and requires SAS to use the default value of 1.
MAX: sets the number of buffers to 2,147,483,647.

Details

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

BUFNO= applies to SAS data sets that are opened for input, output, or update.

Using BUFNO= can improve execution time by limiting the number of input/output operations that are required for a particular SAS data set. The improvement in execution time, however, comes at the expense of increased memory consumption.

Under OpenVMS, the maximum number of buffers that you can allocate is determined by the amount of memory available. However, it is unusual to specify more than 10.

You might want to vary the value of the BUFNO= system option if you are trying to maximize memory usage or the number of observations per page.