Chapter 5. Reading SAS Data Sets

1. What statement is used to read a SAS data set in a DATA step?

[SET statememt]

 

 

 

2. Which of the following is not created during the compilation phase?

[Compilation phase]   (b)

 

 

• During compilation, SAS creates the program data vector and the descriptor portion of the new data set.
• SAS creates the first observation during the execution phase.
• Comilation 단계에서는 PDV 와 Descriptor 가 생성되며, Execution 단계에서는 첫번째 관측치가 생성된다. 

 

 

 

3. A KEEP statement in a DATA step omits all variables except Name, Color, and Price from the output data set. Are the omitted variables included in the PDV?

   [제거한 변수가 PDV에는 포함되는지]     (a)

 

 

• All of the variables in the input data set are included in the PDV,
• and the variables not listed in the KEEP statement are in the PDV with drop flags set.
• The variables listed in the KEEP statement are the only variables written to the output data set.
• input data set 에 있는 모든 변수가 PDV 에  포함된다 !!   ★
• KEEP statement 에 지정한 변수만이 output data set 에 쓰여진다.

 

 

 

 

 

4. Which procedure can be used to view the permanent labels and formats stored in a data set?

     [data set 에 저장되어 있는 permanent labels and formats은 어떤 구문을 사용해서 보는가?]    (a)

 

 

 

• PROC CONTENTS displays the descriptor portion of a data set,
• and SAS stores permanent labels and formats in the descriptor portion.