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
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. |