Multiple Execute Commands

Syntax pasted from dialog boxes or copied from the log or the journal may contain EXECUTE commands. When you run commands from a syntax window, EXECUTE commands are generally unnecessary and may slow performance, particularly with larger data files, because each EXECUTE command reads the entire data file. For more information, see EXECUTE and Command Order.

Lag Functions

One notable exception is transformation commands that contain lag functions. In a series of transformation commands without any intervening EXECUTE commands or other commands that read the data, lag functions are calculated after all other transformations, regardless of command order. For example,


COMPUTE lagvar=LAG(var1).
COMPUTE var1=var1*2.

and


COMPUTE lagvar=LAG(var1).
EXECUTE.
COMPUTE var1=var1*2.

yield very different results for the value of lagvar, since the former uses the transformed value of var1 while the latter uses the original value.