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SAS System Options

BUFSIZE= System Option

Specifies the permanent buffer page size for output SAS data sets.
Valid in: configuration file, SAS invocation, OPTIONS statement, SAS System Options window
Category: Files: SAS Files
System administration: Performance
See: BUFSIZE= System Option under Windows UNIX OpenVMS

Syntax Description
See Also


BUFSIZE=n| nK | nM | nG | nT |hexX | MAX

Syntax Description

n | nK | nM | nG | nT

specifies the page size in multiples of 1 (bytes); 1,024 (kilobytes); 1,048,576 (megabytes); 1,073,741,824 (gigabytes); or 1,099,511,627,776 (terabytes). For example, a value of 8 specifies 8 bytes, and a value of 3m specifies 3,145,728 bytes.

The default is 0, which causes SAS to use the minimum optimal page size for the operating environment.


specifies the page size 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 page size to 45 bytes.


sets the page size 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 bytes.


The page size is the amount of data that can be transferred from a single input/output operation to one buffer. The page size is a permanent attribute of the data set and is used when the data set is processed.

A larger page size can improve execution time by reducing the number of times SAS has to read from or write to the storage medium. However, the improvement in execution time comes at the expense of increased memory consumption.

To change the page size, use a DATA step to copy the data set and either specify a new page or use the SAS default.

Note:   If you use the COPY procedure to copy a data set to another library that is allocated with a different engine, the specified page size of the data set is not retained.  [cautionend]

Operating Environment Information:   The default value for BUFSIZE= is determined by your operating environment and is set to optimize sequential access. To improve performance for direct (random) access, you should change the value for BUFSIZE=. For the default setting and possible settings for direct access, see the BUFSIZE= system option in the SAS documentation for your operating environment.  [cautionend]

Operating Environment Information:    The syntax that is shown here applies to the OPTIONS statement. On the command line or in a configuration file, the syntax is specific to your operating environment. For details, see the SAS documentation for your operating environment.  [cautionend]


The BUFSIZE= system option can be overridden by the BUFSIZE= data set option.

See Also

Data Set Option:

BUFSIZE= Data Set Option

System Option:

BUFNO= System Option

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