在查询 “desc dba_data_files” 时，在我的Oracle DataGuard 11.2.0.1.0物理待机上显示关于 “ORA-04043: 对象dba_data_files不存在” 的错误？？

嗨，
当我在Oracle DataGuard 11.2.0.1.0物理备用上使用SQL命令 “desc dba_data_files” 和 “desc dba_temp_files” 查询表 “dba_data_files” 和 “dba_temp_files” 的描述时，出现错误，内容如下，

SYS@standby> desc dba_data_files;
ERROR:
ORA-04043: object dba_data_files does not exist
 
SYS@standby> desc dba_temp_files;
ERROR:
ORA-04043: object dba_temp_files does not exist

但是查询视图 'dba_tablespaces '是可以的，检查如下，

SYS@standby> desc dba_tablespaces;
Name                                                              Null?    Type
----------------------------------------------------------------- -------- --------------------------------------------
TABLESPACE_NAME                                                   NOT NULL VARCHAR2(30)
BLOCK_SIZE                                                        NOT NULL NUMBER
INITIAL_EXTENT                                                             NUMBER
NEXT_EXTENT                                                                NUMBER
MIN_EXTENTS                                                       NOT NULL NUMBER
MAX_EXTENTS                                                                NUMBER
MAX_SIZE                                                                   NUMBER
PCT_INCREASE                                                               NUMBER
MIN_EXTLEN                                                                 NUMBER
STATUS                                                                     VARCHAR2(9)
CONTENTS                                                                   VARCHAR2(9)
LOGGING                                                                    VARCHAR2(9)
FORCE_LOGGING                                                              VARCHAR2(3)
EXTENT_MANAGEMENT                                                          VARCHAR2(10)
ALLOCATION_TYPE                                                            VARCHAR2(9)
PLUGGED_IN                                                                 VARCHAR2(3)
SEGMENT_SPACE_MANAGEMENT                                                   VARCHAR2(6)
DEF_TAB_COMPRESSION                                                        VARCHAR2(8)
RETENTION                                                                  VARCHAR2(11)
BIGFILE                                                                    VARCHAR2(3)
PREDICATE_EVALUATION                                                       VARCHAR2(7)
ENCRYPTED                                                                  VARCHAR2(3)
COMPRESS_FOR                                                               VARCHAR2(12)

现在，如何为我解决这个问题？谢谢!

最好的问候
赵全文

如果您的数据库处于挂载状态 (如果正在进行恢复，则可能是您的备用状态)，则无法看到所有字典结构，因为数据库未打开。只有通过 * instance * 正在运行的事实可以看到的那些结构是可访问的。

例如，在我的12.2数据库

SQL> startup mount
ORACLE instance started.

Total System Global Area  838860800 bytes
Fixed Size                  8752376 bytes
Variable Size             343933704 bytes
Database Buffers          478150656 bytes
Redo Buffers                8024064 bytes
Database mounted.
SQL> desc dba_data_files
ERROR:
ORA-04043: object dba_data_files does not exist

SQL> desc dba_tablespaces
ERROR:
ORA-04043: object dba_tablespaces does not exist

SQL> desc v$session
 Name                                                                    Null?    Type
 ----------------------------------------------------------------------- -------- --------------------------
 SADDR                                                                            RAW(8)
 SID                                                                              NUMBER
 SERIAL#                                                                          NUMBER
 AUDSID                                                                           NUMBER
 PADDR                                                                            RAW(8)
 USER#                                                                            NUMBER
 USERNAME                                                                         VARCHAR2(128)
 COMMAND                                                                          NUMBER
 OWNERID                                                                          NUMBER
 TADDR                                                                            VARCHAR2(16)
 LOCKWAIT                                                                         VARCHAR2(16)
 STATUS                                                                           VARCHAR2(8)
 SERVER                                                                           VARCHAR2(9)
 SCHEMA#                                                                          NUMBER
 SCHEMANAME                                                                       VARCHAR2(128)
 OSUSER                                                                           VARCHAR2(128)
 PROCESS                                                                          VARCHAR2(24)
 MACHINE                                                                          VARCHAR2(64)
 PORT                                                                             NUMBER
 TERMINAL                                                                         VARCHAR2(16)
 PROGRAM                                                                          VARCHAR2(64)
 TYPE                                                                             VARCHAR2(10)
 SQL_ADDRESS                                                                      RAW(8)
 SQL_HASH_VALUE                                                                   NUMBER
 SQL_ID                                                                           VARCHAR2(13)
 SQL_CHILD_NUMBER                                                                 NUMBER
 SQL_EXEC_START                                                                   DATE
 SQL_EXEC_ID                                                                      NUMBER
 PREV_SQL_ADDR                                                                    RAW(8)
 PREV_HASH_VALUE                                                                  NUMBER
 PREV_SQL_ID                                                                      VARCHAR2(13)
 PREV_CHILD_NUMBER                                                                NUMBER
 PREV_EXEC_START                                                                  DATE
 PREV_EXEC_ID                                                                     NUMBER
 PLSQL_ENTRY_OBJECT_ID                                                            NUMBER
 PLSQL_ENTRY_SUBPROGRAM_ID                                                        NUMBER
 PLSQL_OBJECT_ID                                                                  NUMBER
 PLSQL_SUBPROGRAM_ID                                                              NUMBER
 MODULE                                                                           VARCHAR2(64)
 MODULE_HASH                                                                      NUMBER
 ACTION                                                                           VARCHAR2(64)
 ACTION_HASH                                                                      NUMBER
 CLIENT_INFO                                                                      VARCHAR2(64)