Reduce field lengths by converting the field using a format.

For lengthy fields in datasets with large numbers of observations, space can be saved by reformatting the value into a different value and hence holding a smaller field. The following example reads the inventory file, selecting only installations with certain products.

Proc Format;
   InValue Prods ‘A12345’=1
                ‘A23456’=2
              ‘A34567’=3
              ‘A45678’=4
                 Other=0;

Data Invents(Keep=Instid ProdId);
   Length ProdId 2;
   Infile Invents;
   Input @15 ProdId Prods.@;
   If ProdId;
   Input @1 InstId $12.;

This new dataset holds only 14 bytes per observation rather than 18.