Chapter 18: Modifying SAS Data Sets and Tracking Changes
Correct answer: c
The PRIMARY KEY integrity
constraint includes both the NOT NULL and UNIQUE constraints.
Correct answer: d
To initiate an audit
on an existing SAS data set with the DATASETS procedure, you specify
the data set in the AUDIT statement, and then you specify the INITIATE
statement. You specify the library with the LIB= option.
Correct answer: c
In
the MODIFY statement, you specify the master data set followed by
the transaction data set. Then you specify the key variable in the
BY statement.
Correct answer: c
The value of _IORC_
is a numeric return code that indicates the status of the most recently
executed I/O operation. Checking the value of this variable allows
you to detect abnormal I/O conditions and direct execution in particular
ways.
Correct answer: d
In the MODIFY statement,
you list the SAS data set that you want to modify. Then you use the
IC CREATE statement to create the integrity constraint. This integrity
constraint is a CHECK constraint with a WHERE clause to specify the
condition that the variable values must meet.
Correct answer: b
The MODIFY statement
in a DATA step can be used only to modify the values in a data set.
It cannot be used to modify the descriptor portion of the data set.
Correct answer: c
Audit trails are used
to track changes that are made to a data set in place.
Correct answer: a
You use the DATASETS
procedure and the MODIFY statement to specify a number of generation
data sets for a data set. The GENMAX= option is used to specify the
number of versions to save. The number you specify includes the base
version.
Correct answer: b
When you use the KEY=
option, you must specify the update that you want to make to the data
set.
Correct answer: a
The
keyword ALL is used to indicate that you want to delete all generations
of the specified data set, including the base version. The keyword
HIST deletes the generation data sets, but saves the base version.