SAS Chapter 20: Controlling Memory Usage

The BUFNO= option specifies the size of each buffer that is used for reading or writing a SAS data set.

The BUFNO= option can improve execution time by limiting the number of input/output operations that are required.

Using the BUFNO= option results in permanent changes to the data set.

Using the BUFNO= option to increase the number of buffers results in decreased memory consumption.

A page is the unit of data transfer between the engine and the operating environment.

A page includes the number of bytes used by the descriptor portion, the data values, and the overhead.

The size of a page is analogous to buffer size.

The size of a page can be changed at any time.

The page size multiplied by the number of pages.

The page size multiplied by the number of observations.

The sum of the page size and the number of pages.

The number of pages multiplied by the number of variables.

Sasfile work.quarter1 open;

Sasfile work.quarter1 load;

Sasfile work.quarter1 bufno=max;

Sasfile work.quarter1 bufsize=max;

The file is available to subsequent DATA and PROC steps or applications until a SASFILE CLOSE statement is executed or until the program ends.

The file is available to subsequent DATA and PROC steps or applications until a SASFILE END statement is executed.

The file is available for subsequent utility or output processing until the program ends.

If the file increases in size during processing, the number of buffers remains the same.