Chapter 23: Reading, Combining, and Modifying SAS Data Sets

Definitions for Reading, Combining, and Modifying SAS Data Sets

In the context of DATA step processing, the terms reading, combining and modifying have these meanings:

Reading a SAS data set		refers to opening a SAS data set and bringing an observation into the program data vector for processing.
Combining SAS data sets		refers to reading data from two or more SAS data sets and processing them by concatenating interleaving one-to-one reading one-to-one merging match-merging updating a master data set with a transaction data set. The methods for combining SAS data sets are defined in "Combining SAS Data Sets: Methods " on page 402.
Modifying SAS data sets		refers to using the MODIFY statement to update information in a SAS data set in place. The MODIFY statement can save disk space because it modifies data in place, without creating a copy of the data set. You can modify a SAS data set with programming statements or with information that is stored in another data set.