CALL SYMDEL is a data step call routine which is used to delete macro variables from the global symbol table.
Macro variables in SAS are used extensively for reusing codes. You can create a multi-usable program in which analysis of variables can be controlled by updating the values of macro variables.
SAS provides an elegant solution to overcome these problems with the CALL SET routine. You can convert data step variables into macro variables with a few lines of code using the %SYSCALL SET routine. This routine also allows you to convert and process one observation of data step variables at a time thus saving memory usage.