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.