Oracle Message ORA-00082 - memory size of string is not in valid set of [1], [2], [4]stringstringstringstringstring

ERRORmemory size of string is not in valid set of [1], [2], [4]stringstringstringstringstring
CAUSEAn invalid length was specified for the POKE command.
ACTIONUse a valid length (either 1, 2, 4, or possibly 8).