An indicator variable is a binary field with length less than 5 (2 bytes).
An indicator array can be defined by declaring the variable element length of 4,0 and specifying the DIM on the definition specification.
On retrieval, an indicator variable is used to show if its associated host variable has been assigned a null value. On assignment to a column, a negative indicator variable is used to indicate that a null value should be assigned.
Indicator variables are declared in the same way as host variables and the declarations of the two can be mixed in any way that seems appropriate to the programmer.