What is the compilation phase in SAS?

The compilation phase in SAS is the initial phase where SAS processes data steps. During this stage, the system reads the entire data step code and translates it into an internal format that the SAS execution engine can understand. This involves several key actions, such as syntax checking, allocation of resources, and creating the program data vector (PDV), which is essential for data processing. Understanding the compilation phase is crucial because it sets up the environment for the next phase, which is execution, where the compiled code is actually run to manipulate or analyze the data.

In contrast, options that reference being the second step, the final phase, or specifically reading data from external files do not accurately describe the compilation phase, which is distinctly about preparing the program for execution rather than processing or executing the data itself.