The system variables are the read-only variables that are used in the transformer stage or routine. They supply the system information, and these variables start with ‘@.’  Few system variables and their uses –  @FALSE  It replaces the value with 0.  @TRUE  It replaces the value with 1.  @INROWNUM  Number of input rows  @OUTROWNUM  Number of output rows per link  @NUMPARTITIONS  Total number of partitions for the stage.  @PARTITIONNUM  Partition number for the particular instance.  @ITERATION  Iteration number of the current loop