In reply to Diego da Vitoria.

The techniques shown here for reducing the size of character variables will usually provide a nice reduction in file size on disk. If your primary concern is file size, these papers provide some excellent resources:
Programming Tricks For Reducing Storage And Work Space by Curtis A. Smith (https://support.sas.com/resources/papers/proceedings/proceedings/sugi27/p023-27.pdf) |
How to Reduce the Disk Space Required by a SAS® Data Set by Selvaratnam Sridharma (https://www.lexjansen.com/nesug/nesug06/io/io18.pdf)