You can use the BUFNO=
system option or data set option to control how many buffers are available
for reading or writing a SAS data set. Using BUFNO= can improve execution
time by limiting the number of input/output operations that are required
for a particular SAS data set. However, the improvement in I/O comes
at the cost of increased memory consumption. The number of buffers
is not a permanent attribute of the data set and is valid only for
the current step or SAS session.
Correct answer: d
A
page is fixed in size when the data set is created, either to a default
value or a specified value. You can use the BUFSIZE= option to control
the page size of an output SAS data set. The new buffer size is permanent.
After it is specified, it is used whenever the data set is processed.
Correct answer: a
The total number of
bytes occupied by a data set equals the page size multiplied by the
number of pages. You can use the CONTENTS procedure to report the
page size and the number of pages.
Correct answer: b
The SASFILE LOAD statement
opens the file, allocates the buffers, and reads the data into memory.
Correct answer: a
When a SAS data file
is opened using the SASFILE statement, the data is held in memory,
and is available to subsequent DATA and PROC steps or applications,
until either a SASFILE CLOSE statement is executed or the SAS session
ends. Though a file that is opened with the SASFILE statement can
be used for subsequent input or update processing, it cannot be used
for subsequent utility or output processing. If the file in-memory
increases in size during processing, the number of buffers also increases.