The match-merging examples in this
book are straightforward. However, match-merging can be more complex,
depending on your data and on the output data set that you want to
create. To predict the results of match-merges correctly, you need
to understand how the DATA step performs match-merges.
When you submit a DATA
step, it is processed in two phases:
-
the compilation phase, in which SAS checks the syntax
of the SAS statements and compiles them (translates them into machine
code). During this phase, SAS also sets up descriptor information
for the output data set and creates the PDV.
-
the execution phase in which the DATA step reads data and executes any subsequent programming ...