实例讲解如何查找某个对象的定义情况

来源：赛迪网    作者：Curitis

在实际的工作中，我们经常需要查找某个对象的定义的情况，本文中我们将针对不同类型的对象分别进行讲解：

一、V$视图和X$视图

普通的用户不能访问V$视图：

SQL> conn lunar/lunar@test1
已连接。
SQL> select * from user_sys_privs;

USERNAME       PRIVILEGE   ADMIN_OPTION
---------- -------------- ------------

SQL> select * from user_role_privs;

USERNAME      GRANTED_ROLE   ADMIN_OPTION DEFAULT_ROLE OS_GRANTED
----------- --------------- ------------ ------------ ----------
LUNAR       CONNECT      NO           YES          NO
LUNAR       RESOURCE     NO           YES          NO
PUBLIC      PLUSTRACE    NO           YES          NO

SQL> select count(*) from v$fixed_table;

select count(*) from v$fixed_table

ORA-00942: 表或视图不存在

必须授权：
SQL> conn /@test1 as sysdba
已连接。
SQL> grant select on v_$fixed_table to lunar;

授权成功。
SQL> conn lunar/lunar@test1
已连接。
SQL>

我们可以发现，得到授权的普通用户仍然只能访问V$开头的视图，而不能直接访问V_$开头的视图，因为实际上V$视图是V_$视图的公有同义词（PUBLIC SYNONYM）要想访问V_$必须带上SYS.V_$。

例如:

SQL> select count(*) from v$fixed_table;

  COUNT(*)
----------
       912

SQL> select count(*) from v_$fixed_table;

select count(*) from v_$fixed_table

ORA-00942: 表或视图不存在

SQL> select count(*) from sys.v_$fixed_table;

  COUNT(*)
----------
       912

SQL>

与此同时，也可以授予用户SELECT any table权限，这样这个用户就可以访问所有的V$视图：

SQL> grant select any table to lunar;

授权成功。

SQL> select * from user_role_privs;

USERNAME         GRANTED_ROLE       ADMIN_OPTION DEFAULT_ROLE OS_GRANTED
------------ --------------------- ------------ ------------ ----------
LUNAR            CONNECT             NO           YES          NO
LUNAR            RESOURCE            NO           YES          NO
PUBLIC           PLUSTRACE           NO           YES          NO

SQL> select * from user_sys_privs;

USERNAME         PRIVILEGE           ADMIN_OPTION
------------ ----------------------- ------------
LUNAR            SELECT ANY TABLE       NO

SQL> select count(*) from v$fixed_table;

  COUNT(*)
----------
       912

SQL> select * from v$fixed_table where rownum<2;

NAME       OBJECT_ID TYPE   TABLE_NUM
---------- ---------- ----- ----------
X$KQFTA    4294950912 TABLE     0

SQL> select * from v_$fixed_table where rownum<2;

select * from v_$fixed_table where rownum<2

ORA-00942: 表或视图不存在

SQL> select * from sys.v_$fixed_table where rownum<2;

NAME       OBJECT_ID  TYPE   TABLE_NUM
---------- ---------- ----- ----------
X$KQFTA    4294950912 TABLE      0

SQL>

通过查询V$FIXED_TABLE视图，我们可以看到大部分V$视图和一些X$视图（还有一些Oracle未公开的视图不在其中）。

 

有人要问，那么这些V$视图又是有什么组成的呢？

通过查询V$FIXED_VIEW_DEFINITION视图，我们可以看到这些V$视图的创建语句：

SQL> conn /@test1 as sysdba
已连接。
SQL> grant select any table to lunar;

授权成功。

SQL> conn lunar/lunar@test1
已连接。
SQL>

SQL> set heading off echo off long 50000 pages 10000

SQL> select * from v$fixed_view_definition where view_name='V$FIXED_TABLE';

V$FIXED_TABLE                  

select  NAME , OBJECT_ID , TYPE , TABLE_NUM from GV$FIXED_TABLE 

where inst_id = USERENV('Instance')

SQL> 

select  NAME , OBJECT_ID , TYPE , TABLE_NUM 
from GV$FIXED_TABLE 
where inst_id = USERENV('Instance')

那么这个GV$FIXED_TABLE视图的定义又是怎样的呢？

SQL> select * from v$fixed_view_definition where view_name='GV$FIXED_TABLE';
GV$FIXED_TABLE                 
select inst_id,kqftanam, kqftaobj, 'TABLE', indx from x$kqfta union all select 

inst_id,kqfvinam, kqfviobj, 'VIEW', 65537 from x$kqfvi union all select 

inst_id,kqfdtnam, kqfdtobj, 'TABLE', 65537 from x$kqfdt

SQL> 

select inst_id,kqftanam, kqftaobj, 'TABLE', indx from x$kqfta 
union all 
select inst_id,kqfvinam, kqfviobj, 'VIEW', 65537 from x$kqfvi 
union all 
select inst_id,kqfdtnam, kqfdtobj, 'TABLE', 65537 from x$kqfdt

此时我们就找到了创建一个V$视图的最低层的信息，即一个V$视图是由哪些X$表构成的。

要找到底层X$表的索引信息，可以查询v$indexed_fixed_column：

SQL> desc v$indexed_fixed_column
Name            Type         Nullable Default Comments 
--------------- ------------ -------- ------- -------- 
TABLE_NAME      VARCHAR2(30) Y                         
INDEX_NUMBER    NUMBER       Y                         
COLUMN_NAME     VARCHAR2(30) Y                         
COLUMN_POSITION NUMBER       Y                         

SQL> 
例如：
SQL> select * from v$indexed_fixed_column where table_name='X$KQFTA';

TABLE_NAME          INDEX_NUMBER COLUMN_NAME  COLUMN_POSITION
------------------ ------------ -------------- ---------------
X$KQFTA               1 ADDR                    0
X$KQFTA               2 INDX                    0

SQL>

一般情况下，V$视图和GV$视图的定义是一样的，只是GV$视图中包含的实例id的信息，常用于OPS或者RAC的系统中，也有少数几个V$视图和GV$视图的定义是有区别的，比如GV$PX_PROCESS和V$PX_PROCESS：

SQL> select * from v$fixed_view_definition where view_name='GV$PX_PROCESS';

GV$PX_PROCESS                  
select a.inst_id, a.kxfpdpnam,  decode(bitand(a.kxfpdpflg, 16), 0, 'IN

USE', 'AVAILABLE'),  b.pid, a.kxfpdpspid, 

c.sid, c.serial#  from x$kxfpdp a, V$PROCESS b, 

V$SESSION c  where bitand(kxfpdpflg, 8) != 0 and  a.kxfpdpspid = b.SPID and

a.kxfpdpspid = c.PROCESS(+)

SQL>
select a.inst_id, a.kxfpdpnam,  

 decode(bitand(a.kxfpdpflg, 16), 0, 'IN USE', 'AVAILABLE'), 
 
 b.pid, a.kxfpdpspid, c.sid, c.serial#  

from x$kxfpdp a, V$PROCESS b, V$SESSION c  

where bitand(kxfpdpflg, 8) != 0 and  
a.kxfpdpspid = b.SPID and  a.kxfpdpspid = c.PROCESS(+)

 

SQL> select * from v$fixed_view_definition where view_name='V$PX_PROCESS';

V$PX_PROCESS 
                  
select  SERVER_NAME, STATUS, PID, SPID, SID, SERIAL#  from GV$PX_PROCESS 

where inst_id = USERENV('Instance')

SQL>
select  SERVER_NAME, STATUS, PID, SPID, SID, SERIAL#  
from GV$PX_PROCESS 
where inst_id = USERENV('Instance')

二、数据字典的组成

下面我们再来将一个数据字典表的定义呢？

SQL> desc dba_views
Name             Type          Nullable  Default Comments                                                    
---------------- ------------ -------- ------- -------
OWNER            VARCHAR2(30)           Owner of the view                                           
VIEW_NAME        VARCHAR2(30)           Name of the view                                            
TEXT_LENGTH      NUMBER         Y        Length of the view text                                     
TEXT             LONG           Y        View text                                                   
TYPE_TEXT_LENGTH NUMBER         Y        Length of the type clause of the object view                
TYPE_TEXT        VARCHAR2(4000) Y        Type clause of the object view                              
OID_TEXT_LENGTH  NUMBER         Y        Length of the WITH OBJECT OID clause of the object view     
OID_TEXT         VARCHAR2(4000) Y        WITH OBJECT OID clause of the object view                   
VIEW_TYPE_OWNER  VARCHAR2(30)   Y        Owner of the type of the view if the view is an object view 
VIEW_TYPE        VARCHAR2(30)   Y        Type of the view if the view is an object view              
SUPERVIEW_NAME   VARCHAR2(30)   Y        Name of the superview, if view is a subview                 

SQL> 


SQL> set heading off echo off long 1000000000 pages 10000
SQL> select text from dba_views where view_name ='DBA_USERS';
select u.name, u.user#, u.password,
m.status,
decode(u.astatus, 4, u.ltime,
5, u.ltime,
6, u.ltime,
8, u.ltime,
9, u.ltime,
10, u.ltime, to_date(NULL)),
decode(u.astatus,
1, u.exptime,
2, u.exptime,
5, u.exptime,
6, u.exptime,
9, u.exptime,
10, u.exptime,
decode(u.ptime, '', to_date(NULL),
decode(pr.limit#, 2147483647, to_date(NULL),
decode(pr.limit#, 0,
decode(dp.limit#, 2147483647, to_date(NULL), u.ptime +
dp.limit#/86400),
u.ptime + pr.limit#/86400)))),
dts.name, tts.name, u.ctime, p.name, u.defschclass, u.ext_username
from sys.user$ u, sys.ts$ dts, sys.ts$ tts, sys.profname$ p,
sys.user_astatus_map m, sys.profile$ pr, sys.profile$ dp
where u.datats# = dts.ts#
and u.resource$ = p.profile#
and u.tempts# = tts.ts#
and u.astatus = m.status#
and u.type# = 1
and u.resource$ = pr.profile#
and dp.profile# = 0
and dp.type#=1
and dp.resource#=1
and pr.type# = 1
and pr.resource# = 1


SQL>

三、如何查找用户自定义的某个表的定义？

在Oracle 9i前，我们可以使用下面的方法：

SQL> select substr(table_name,1,20) tabname,
  2  substr(column_name,1,20)column_name,
  3  rtrim(data_type)||'('||data_length||')' from dba_tab_columns
  4  where owner='&username'
  5  /

TABNAME                              COLUMN_NAME    RTRIM(DATA_TYPE)||'('||DATA_LE
--------------------------- ---------------------   -------
BONUS                                    ENAME                                    VARCHAR2(10)
BONUS                                    JOB                                      VARCHAR2(9)
BONUS                                    SAL         NUMBER(22)
BONUS                                    COMM        NUMBER(22)
DEPT                                     DEPTNO      NUMBER(22)
DEPT                                     DNAME                                    VARCHAR2(14)
DEPT                                     LOC                                      VARCHAR2(13)
DUMMY                                    DUMMY       NUMBER(22)
EMP                                      EMPNO       NUMBER(22)
EMP                                      ENAME                                    VARCHAR2(10)
EMP                                      JOB                                      VARCHAR2(9)
EMP                                      MGR         NUMBER(22)
EMP                                      HIREDATE    DATE(7)
EMP                                      SAL         NUMBER(22)
EMP                                      COMM        NUMBER(22)
EMP                                      DEPTNO      NUMBER(22)
SALGRADE                                 GRADE       NUMBER(22)
SALGRADE                                 LOSAL       NUMBER(22)
SALGRADE                                 HISAL       NUMBER(22)

19 rows selected

SQL>

从Oracle 9i开始，我们可以使用dbms_metadata.get_ddl来找到对象的定义。

例如：

SQL> @C:\TEMP\get_obj_sql.sql
SQL> set heading off echo off pages 10000 long 90000
输入 object_type 的值:  TABLE
输入 object_name 的值:  EMP
输入 object_owner 的值:  LUNAR
原值    1: select dbms_metadata.get_ddl(upper('&OBJECT_TYPE'),upper('&OBJECT_NAME'),upper('&OBJECT_O
WNER')) from dual
新值    1: select dbms_metadata.get_ddl(upper('TABLE'),upper('EMP'),
upper('LUNAR')) from dual


  CREATE TABLE "LUNAR"."EMP"
   (    "EMPNO" NUMBER(4,0) NOT NULL ENABLE,
        "ENAME" VARCHAR2(10),
        "JOB" VARCHAR2(9),
        "MGR" NUMBER(4,0),
        "HIREDATE" DATE,
        "SAL" NUMBER(7,2),
        "COMM" NUMBER(7,2),
        "DEPTNO" NUMBER(2,0)
   ) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
  TABLESPACE "SYSTEM"

 

SQL>

 

大家需要注意，这个查询是需要临时表空间的，所以如果临时表空间不够查询就会有问题了：

SQL> @C:\TEMP\get_obj_sql.sql
SQL> set heading off echo off pages 10000 long 90000
输入 object_type 的值:  TABLE
输入 object_name 的值:  DEPT
输入 object_owner 的值:  LUNAR
原值    1: select dbms_metadata.get_ddl(upper('&OBJECT_TYPE'),upper('&OBJECT_NAME'),upper('&OBJECT_O
WNER')) from dual
新值    1: select dbms_metadata.get_ddl(upper('TABLE'),upper('DEPT'),upper('LUNAR')) from dual
ERROR:
ORA-25153: 临时表空间为空
ORA-06512: 在"SYS.DBMS_LOB", line 424
ORA-06512: 在"SYS.DBMS_METADATA", line 557
ORA-06512: 在"SYS.DBMS_METADATA", line 1221
ORA-06512: 在line 1

 

未选定行

SQL>
SQL> SELECT NAME FROM V$TEMPFILE;

未选定行

SQL> SELECT NAME FROM V$TABLESPACE;

NAME
------------------------------
SYSTEM
UNDOTBS1
TEMP
INDX
USERS

SQL> ALTER TEMPORARY TABLESPACE TEMP ADD TEMPFILE 'D:\oracle92\oradata\test1\TEMP01.DBF' SIZE 10M;
ALTER TEMPORARY TABLESPACE TEMP ADD TEMPFILE 'D:\oracle92\oradata\test1\TEMP01.DBF' SIZE 10M
      *
ERROR 位于第 1 行:
ORA-00940: 无效的 ALTER 命令


SQL> ALTER TABLESPACE TEMP ADD TEMPFILE 'D:\oracle92\oradata\test1\TEMP01.DBF' SIZE 10M;

表空间已更改。

SQL> @C:\TEMP\get_obj_sql.sql
SQL> set heading off echo off pages 10000 long 90000
输入 object_type 的值:  TABLE
输入 object_name 的值:  EMP
输入 object_owner 的值:  LUNAR
原值    1: select dbms_metadata.get_ddl(upper('&OBJECT_TYPE'),upper('&OBJECT_NAME'),upper('&OBJECT_O
WNER')) from dual
新值    1: select dbms_metadata.get_ddl(upper('TABLE'),upper('EMP'),upper('LUNAR')) from dual


  CREATE TABLE "LUNAR"."EMP"
   (    "EMPNO" NUMBER(4,0) NOT NULL ENABLE,
        "ENAME" VARCHAR2(10),
        "JOB" VARCHAR2(9),
        "MGR" NUMBER(4,0),
        "HIREDATE" DATE,
        "SAL" NUMBER(7,2),
        "COMM" NUMBER(7,2),
        "DEPTNO" NUMBER(2,0)
   ) PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
  STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
  PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT)
  TABLESPACE "SYSTEM"

 

SQL>
SQL>

dbms_metadata.get_ddl也可以用来查询其他对象的创建语句，使用的方法如下；

select dbms_metadata.get_ddl('对象类型','对象名','用户名') from dual;

例如:

oracle@cs_db02:/arch1/lunar/tools > get_obj_sql.sh procedure aa misc
Connected.


CREATE OR REPLACE PROCEDURE "MISC"."AA" is
begin
delete from error_tip;
end aa;