datatype class %Library.DataType
ODBC Type: VARCHAR
Note that data types do not have to inherit from this class in order to be a data type but this is used by the built in data types.
Override this parameter value to specify what value should be used as a null marker when a property of the type is used in a subscript of an index map. The default null marker used is -1E14, if none is specfied for the datatype. However %Library.PosixTime and %Library.BigInt datatypes could have values that collate before -1E14, and this means null values would not sort before all non-NULL values.