这里专门罗列了一些数据库系统instance与database、service以及resource的字典，来了解
数据库的重要信息。

---查看数据库系统所有参数的字典：

Select * from v$system_parameter;

sys@PROD>desc v$system_parameter;

 Name                                      Null?    Type

 ----------------------------------------- -------- ----------------------------

 NUM                                                NUMBER

 NAME                                               VARCHAR2(80)

 TYPE                                               NUMBER

 VALUE                                              VARCHAR2(4000)

 DISPLAY_VALUE                                      VARCHAR2(4000)

 ISDEFAULT                                          VARCHAR2(9)

 ISSES_MODIFIABLE                                   VARCHAR2(5)

 ISSYS_MODIFIABLE                                   VARCHAR2(9)

 ISINSTANCE_MODIFIABLE                              VARCHAR2(5)

 ISMODIFIED                                         VARCHAR2(8)

 ISADJUSTED                                         VARCHAR2(5)

 ISDEPRECATED                                       VARCHAR2(5)

 ISBASIC                                            VARCHAR2(5)

 DESCRIPTION                                        VARCHAR2(255)

 UPDATE_COMMENT                                     VARCHAR2(255)

 HASH                                               NUMBER

---查看实例：

SELECT * from v$instance;   --查看单实例的实例信息

SELECT * from gv$instance;  --查看集群中的实例信息

---查看数据库：

select * from v$database;   --查看单实例的数据库信息

select * from gv$database;  --查看集群中的数据库信息

---查看服务器相关信息：

SELECT * FROM V$SERVICES;

SELECT * FROM GV$SERVICES;

#查看服务名。

--与数据库服务相关的信息视图：

SELECT * FROM V$SERVICE_EVENT;

SELECT * FROM GV$SERVICE_EVENT;

 --数据库服务的相关统计信息：

SELECT * FROM V$SERVICE_STATS;

SELECT * FROM GV$SERVICE_STATS;

 --数据库服务等待事件相关信息：

SELECT * FROM V$SERVICE_WAIT_CLASS;

SELECT * FROM GV$SERVICE_WAIT_CLASS;

---查看处理器进程信息：

Select * from v$process;

SQL> desc v$process;

 Name                                      Null?    Type

 ----------------------------------------- -------- ----------------------------

 ADDR                                               RAW(8)

 PID                                                NUMBER

 SPID                                               VARCHAR2(24)

 PNAME                                              VARCHAR2(5)

 USERNAME                                           VARCHAR2(15)

 SERIAL#                                            NUMBER

 TERMINAL                                           VARCHAR2(30)

 PROGRAM                                            VARCHAR2(48)

... ...

---查看资源信息：

Select * from v$resource;

SQL> desc v$resource;

 Name                                      Null?    Type

 ----------------------------------------- -------- ----------------------------

 ADDR                                               RAW(8)

 TYPE                                               VARCHAR2(2)

 ID1                                                NUMBER

 ID2                                                NUMBER