You can use the SASFILE
statement to open a SAS data set. SAS attempts to allocate enough
buffers to hold the entire data set in memory. If enough memory is
available, then the entire data set is kept in memory until the data
set is closed. If enough memory is not available, then SAS allocates
as many buffers as it can. If your file is very large or if SAS is
already using a large amount of memory, then using the SASFILE statement
will not help.
When the SASFILE statement
executes the first time, SAS opens the file. Subsequent DATA and PROC
steps use the file without having to open it again because the file
remains in memory. The file remains open until a second SASFILE statement
closes it, or until the program or session ends. For more information,
see
SASFILE Statement in SAS Statements: Reference.