Indicator variables are treated as flags which are affiliated with the owner or host variables.we can specify every owner(host) variable with a indicator variable.These are to be characterised as a 2 Byte integer "short" type, while ur using it in a Query(i.e ...embedded SQL statements..) these should be prefixed by a colon and directly pursue its owner variable or u may use "INDICATOR" keyword in between host and sign variables.
Examples:
int myNo;
short ind_myNo;
//here if u want to associate indicator variable ind_myNo with the host variable myNo
//the embedded sql looks like follows:
EXEC SQL SELECT COLUMN NAME into :myNo:ind_myNo from TABLENAME
OR
EXEC SQL SELECT COLUMN NAME into :myNo INDICATOR :ind_myNo from TABLENAME
