SAS Certification Prep Guide, 5th Edition

Chapter 10: Combining SAS Data Sets

1. Correct answer: a

   This example is a case of one-to-one matching, which requires multiple SET statements. Where same-named variables occur, values that are read from the second data set replace those that are read from the first data set. Also, the number of observations in the new data set is the number of observations in the smallest original data set.
2. Correct answer: b

   This is a case of concatenation, which requires a list of data set names in the SET statement and one or more BY variables in the BY statement. Notice that observations in each BY group are read sequentially, in the order in which the data sets and BY variables are listed. The new data set contains all the variables from all the ...