If you have already applied optimization techniques
but still experience lengthy processing times or excessive memory
usage, the size of your data sets might be very large. In that case,
further improvement might not be possible.
You can estimate the
size of a data set by creating a dummy data set that contains the
same variables as your data set. Run the CONTENTS procedure, which
shows the size of each observation. Multiply the size by the number
of observations in your data set to obtain the total number of bytes
that must be processed. You can compare processing statistics with
smaller data sets to determine whether the performance of the large
data sets is in proportion to their size. If not, further optimization
might still be possible.
Note: When you use this technique
to calculate the size of a data set, you obtain only an estimate.
Internal requirements, such as the storage of variable names, might
cause the actual data set size to be slightly different.