docs: public int isNullable( int index ) throws OdaException
  	{
  		int type =  getColumnType( index );
  		if (sqlTypesMayBeNull.containsKey(type)){
  			return IResultSetMetaData.columnNullable;
  		}else{
  			return IResultSetMetaData.columnNoNulls;
  		}
  	}