Using a Few Key Elements of SAS DATA Step Code and a Couple of Procedures to Optimize the Observation Length of a Data Set
The SAS DATA step supports quite a few statements and functions. Many of these are usually accompanied with acceptable default values. Due to the nature of SAS programming, however, the function defaults are sometimes overly generous. This is particularly true of length specifications for both the numeric and character variables. With the default of 8 bytes for numeric variables (the equivalent of double-float notation in other languages) and the default length of character variables sometimes as long as 200 bytes, the potential for shortening variable lengths is quite high. Some standard SAS functions and procedures enables one to shorten variable lengths quite easily. Shorter variable lengths mean shorter observation lengths, and shorter observation lengths enable faster I/O processing.