来源于SAS OnlineTutor: Advanced SAS， pdf版本
1. Controlling Data Storage Space
Introduction
In many computing environments, data storage space is a limited resource. Therefore, it might be more important for you to
conserve data storage space than to conserve other resources.
When you store your data in a SAS data file, you use the sum of the data storage space that is required for the following:
the descriptor portion
the observations
any storage overhead
any associated indexes.
In this lesson you learn to use a variety of techniques for minimizing the amount of space that your SAS data files occupy.
2。 Controlling Memory Usage
Introduction
As you have learned, there is no single set of programming techniques that is most efficient or appropriate in all situations.
However, if reducing execution time is an important consideration in your computing environment, one way of achieving that
goal is to reduce the number of times SAS has to read from or write to the storage medium.
In this lesson you learn to use options and a statement to control the size and number of data buffers, which in turn can affect
your programs' execution times by reducing the number of I/O operations that SAS must perform.