Base SAS 9.1.3 Procedures Guide - Acsu Buffalo

The DATASETS Procedure 4 Procedure Execution 353
Concepts: DATASETS Procedure
Procedure Execution
Execution of Statements
When you start the DATASETS procedure, you specify the procedure input library in
the PROC DATASETS statement. If you omit a procedure input library, the procedure
processes the current default SAS data library (usually the WORK data library). To
specify a new procedure input library, issue the DATASETS procedure again.
Statements execute in the order they are written. For example, if you want to see
the contents of a data set, copy a data set, and then visually compare the contents of
the second data set with the first, the statements that perform those tasks must appear
in that order (that is, CONTENTS, COPY, CONTENTS).
RUN-Group Processing
PROC DATASETS supports RUN-group processing. RUN-group processing enables
you to submit RUN groups without ending the procedure.
The DATASETS procedure supports four types of RUN groups. Each RUN group is
defined by the statements that compose it and by what causes it to execute.
Some statements in PROC DATASETS act as implied RUN statements because they
cause the RUN group preceding them to execute.
The following list discusses what statements compose a RUN group and what causes
each RUN group to execute:
3 The PROC DATASETS statement always executes immediately. No other
statement is necessary to cause the PROC DATASETS statement to execute.
Therefore, the PROC DATASETS statement alone is a RUN group.
3 The MODIFY statement, and any of its subordinate statements, form a RUN
group. These RUN groups always execute immediately. No other statement is
necessary to cause a MODIFY RUN group to execute.
3 The APPEND, CONTENTS, and COPY statements (including EXCLUDE and
SELECT, if present), form their own separate RUN groups. Every APPEND
statement forms a single-statement RUN group; every CONTENTS statement
forms a single-statement RUN group; and every COPY step forms a RUN group.
Any other statement in the procedure, except those that are subordinate to either
the COPY or MODIFY statement, causes the RUN group to execute.
3 One or more of the following statements form a RUN group:
3 AGE
3 CHANGE
3 DELETE
3 EXCHANGE
3 REPAIR
3 SAVE
If any of these statements appear in sequence in the PROC step, the sequence
forms a RUN group. For example, if a REPAIR statement appears immediately
after a SAVE statement, the REPAIR statement does not force the SAVE