As per PeopleBooks

For the user, running an SQR program is a one-step process. For SQR, however, two steps are involved: compiling the program and running it. When compiling a program, SQR:

-Reads, interprets, and validates the program.
-Preprocesses substitution variables and certain commands: ASK, #DEFINE, #INCLUDE, #IF, and #IFDEF.
-Validates SQL statements.
-Performs the SETUP section.