SAS Certification Prep Guide, 4th Edition

Chapter 22: Using Best Practices

1. Correct answer: b

   As SAS processes a larger subset of the data, more CPU resources are required. However, positioning of the subsetting IF statement in a DATA step can affect performance and efficiency.
2. Correct answer: c

   The DATA step is the only technique that can be used to modify both data values and variable attributes. The DATASETS procedure enables you to modify only variable attributes.
3. Correct answer: d

   For selecting observations, a WHERE statement is more efficient than a subsetting IF statement because it examines what is in the input page buffer and selects observations before they are loaded into the program data vector, which results in a savings in CPU operations.
4. Correct answer: ...