You can use global macro
variables in SPD Server to simplify your work. Global macro variables
use default values that are set by SPD Server and that operate in
the background. You can make global changes to the values of macro
variables in your code by specifying a new default setting for the
specified variable. The new default setting is applied to all macro
variables in the code that you submit to SPD Server. You can override
the setting for a single macro variable by using a table option to
change the setting for only the specified table.
The default macro variable
values automate processing decisions. The default settings provide
good performance. However, optimal performance requires changes to
the default settings of some macro variables. Before you make changes
to the default settings, consider conducting performance testing first.
After you quantify performance parameters by using several macro variable
settings, you can customize SPD Server so that it solves your business
or data problems with maximum efficiency.
Each SPD Server installation
is different. You might want to change many values, or just a few.
Either way, macro variables are flexible and easy to manipulate.
Use a %LET statement
to change macro variable values. You can place the macro variable
assignment anywhere in the open code of a SAS program except in the
data lines. The most convenient location for your %LET statements
to initialize macro variables is in your autoexec.sas file or at the
beginning of a program. The macro variable assignment is valid for
the duration of your session or the executing program. Macro variable
values remain in effect until they are changed by a subsequent assignment.
Assignments for macro
variables with YES or NO arguments must be uppercase.
Because SPD Server macro
variables operate behind the scenes, you cannot query SPD Server to
determine the status of a macro variable. SAS does not know about
the status of macro variables. If you want to know which SPD Server
macro variables are in effect, or what their default values are, you
can use PROC SPDO.