oracle恢复误删除数据,解除锁定等非常经典实用方法

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注意:数据库版本是10g,不过大部分9i的也适用,闪回9i就没有.

1.曾经不小心把开发库的数据库表全部删除,当时吓的要死。结果找到下面的语句恢复到了1个小时之前的数据!很简单。

注意使用管理员登录系统:

select * from 表名 as of timestamp sysdate-1/12 //查询两个小时前的某表数据!既然两小时以前的数据都得到了,继续怎么做,知道了吧。。

如果drop了表,怎么办??见下面:

drop table 表名;

数据库误删除表之后恢复:( 绝对ok,我就做过这样的事情,汗 )不过要记得删除了哪些表名。
flashback table 表名 to before drop;

2.查询得到当前数据库中锁,以及解锁:

查锁
SELECT /*+ rule */ s.username,
decode(l.type,'TM','TABLE LOCK',
'TX','ROW LOCK',
NULL) LOCK_LEVEL,
o.owner,o.object_name,o.object_type,
s.sid,s.serial#,s.terminal,s.machine,s.program,s.osuser
FROM v$session s,v$lock l,dba_objects o
WHERE l.sid = s.sid
AND l.id1 = o.object_id(+)
AND s.username is NOT NULL;

解锁
alter system kill session 'sid,serial';
如果解不了。直接倒os下kill进程kill -9 spid

ORA-28000:账户被锁定

因为密码输入错误多次用户自动被锁定.

解决办法:alter user user_name account unlock;

3.关于查询数据库用户,权限的相关语句:

Sql代码

  1. 1.查看所有用户:
  2. select*fromdba_user;
  3. select*fromall_users;
  4. select*fromuser_users;
  5. 2.查看用户系统权限:
  6. select*fromdba_sys_privs;
  7. select*fromall_sys_privs;
  8. select*fromuser_sys_privs;
  9. 3.查看用户对象权限:
  10. select*fromdba_tab_privs;
  11. select*fromall_tab_privs;
  12. select*fromuser_tab_privs;
  13. 4.查看所有角色:
  14. select*fromdba_roles;
  15. 5.查看用户所拥有的角色:
  16. select*fromdba_role_privs;
  17. select*fromuser_role_privs;
1.查看所有用户:
select * from dba_user;
select * from all_users;
select * from user_users;


2.查看用户系统权限:
select * from dba_sys_privs;
select * from all_sys_privs;
select * from user_sys_privs;


3.查看用户对象权限:
select * from dba_tab_privs;
select * from all_tab_privs;
select * from user_tab_privs;


4.查看所有角色:
select * from dba_roles;


5.查看用户所拥有的角色:
select * from dba_role_privs;
select * from user_role_privs;

4.几个经常用到的oracle视图:注意表名使用大写....................

Sql代码

  1. 1.查询oracle中所有用户信息
  2. select*fromdba_user;
  3. 2.只查询用户和密码
  4. selectusername,passwordfromdba_users;
  5. 3.查询当前用户信息
  6. select*fromdba_ustats;
  7. 4.查询用户可以访问的视图文本
  8. select*fromdba_varrays;
  9. 5.查询数据库中所有视图的文本
  10. select*fromdba_views;
  11. 6.查询全部索引
  12. select*fromuser_indexes;
  13. 查询全部表格
  14. select*fromuser_tables;
  15. 查询全部约束
  16. select*fromuser_constraints;
  17. 查询全部对象
  18. select*fromuser_objects;
1. 查询oracle中所有用户信息
       select  * from dba_user;
   2. 只查询用户和密码
       select username,password from dba_users;
   3. 查询当前用户信息
       select * from dba_ustats;
   4. 查询用户可以访问的视图文本
       select * from dba_varrays;
   5. 查询数据库中所有视图的文本
       select * from dba_views;
6.查询全部索引 
select * from user_indexes;
查询全部表格
      select * from user_tables;
         查询全部约束
      select * from user_constraints;
          查询全部对象
      select * from user_objects;

5.查看当前数据库中正在执行的语句,然后可以继续做很多很多事情,例如查询执行计划等等

Sql代码

  1. (1).查看相关进程在数据库中的会话
  2. Selecta.sid,a.serial#,a.program,a.status,
  3. substr(a.machine,1,20),a.terminal,b.spid
  4. fromv$sessiona,v$processb
  5. wherea.paddr=b.addr
  6. andb.spid=&spid;
  7. (2).查看数据库中被锁住的对象和相关会话
  8. selecta.sid,a.username,
  9. c.owner,c.object_name
  10. fromv$sessiona,v$locked_objectb,all_objectsc
  11. wherea.sid=b.session_idand
  12. c.object_id=b.object_id;
  13. (3).查看相关会话正在执行的SQL
  14. selectsql_textfromv$sqlareawhereaddress=
  15. (selectsql_addressfromv$sessionwheresid=&sid);
(1).查看相关进程在数据库中的会话   
  Select   a.sid,substr(a.machine,b.spid   
  from   v$session   a,v$process   b   
  where   a.paddr=b.addr   
  and   b.spid   =   &spid;   
    
  (2).查看数据库中被锁住的对象和相关会话   
  select   a.sid,c.owner,c.object_name     
  from   v$session   a,v$locked_object   b,all_objects   c   
  where   a.sid=b.session_id   and   
  c.object_id   =   b.object_id;   
    
  (3).查看相关会话正在执行的SQL   
  select   sql_text   from   v$sqlarea   where   address   =     
  (   select   sql_address   from   v$session   where   sid   =   &sid   );

6.查询表的结构:表名大写!!

select t.COLUMN_NAME,
t.DATA_TYPE,
nvl(t.DATA_PRECISION,t.DATA_LENGTH),
nvl(T.DATA_SCALE,0),
c.comments
from all_tab_columns t,user_col_comments c
whEre t.TABLE_NAME = c.table_name
and t.COLUMN_NAME = c.column_name
and t.TABLE_NAME = UPPER('OM_EMPLOYEE_T')
order by t.COLUMN_ID

7.行列互换:

Sql代码

  1. 建立一个例子表:
  2. CREATETABLEt_col_row(
  3. IDINT,
  4. c1VARCHAR2(10),
  5. c2VARCHAR2(10),
  6. c3VARCHAR2(10));
  7. INSERTINTOt_col_rowVALUES(1,'v11','v21','v31');
  8. INSERTINTOt_col_rowVALUES(2,'v12','v22',NULL);
  9. INSERTINTOt_col_rowVALUES(3,'v13',NULL,'v33');
  10. INSERTINTOt_col_rowVALUES(4,'v24','v34');
  11. INSERTINTOt_col_rowVALUES(5,'v15',NULL);
  12. INSERTINTOt_col_rowVALUES(6,'v35');
  13. INSERTINTOt_col_rowVALUES(7,NULL);
  14. COMMIT;
  15. 下面的是列转行:创建了一个视图
  16. CREATEviewv_row_colAS
  17. SELECTid,'c1'cn,c1cv
  18. FROMt_col_row
  19. UNIONALL
  20. SELECTid,'c2'cn,c2cv
  21. FROMt_col_row
  22. UNIONALL
  23. SELECTid,'c3'cn,c3cvFROMt_col_row;
  24. 下面是创建了没有空值的一个竖表:
  25. CREATEviewv_row_col_notnullAS
  26. SELECTid,c1cv
  27. FROMt_col_row
  28. wherec1isnotnull
  29. UNIONALL
  30. SELECTid,c2cv
  31. FROMt_col_row
  32. wherec2isnotnull
  33. UNIONALL
  34. SELECTid,c3cv
  35. FROMt_col_row
  36. wherec3isnotnull;
建立一个例子表:
CREATE TABLE t_col_row( 
ID INT,c1 VARCHAR2(10),c2 VARCHAR2(10),c3 VARCHAR2(10)); 
INSERT INTO t_col_row VALUES (1,'v11','v21','v31'); 
INSERT INTO t_col_row VALUES (2,'v12','v22',NULL); 
INSERT INTO t_col_row VALUES (3,'v13',NULL,'v33'); 
INSERT INTO t_col_row VALUES (4,'v24','v34'); 
INSERT INTO t_col_row VALUES (5,'v15',NULL); 
INSERT INTO t_col_row VALUES (6,'v35'); 
INSERT INTO t_col_row VALUES (7,NULL); 
COMMIT; 

下面的是列转行:创建了一个视图
CREATE view v_row_col AS
SELECT id,'c1' cn,c1 cv
FROM t_col_row
UNION ALL
SELECT id,'c2' cn,c2 cv
FROM t_col_row
UNION ALL
SELECT id,'c3' cn,c3 cv FROM t_col_row;

下面是创建了没有空值的一个竖表:
CREATE view v_row_col_notnull AS
SELECT id,c1 cv
 FROM t_col_row 
where c1 is not null
UNION ALL
SELECT id,c2 cv
 FROM t_col_row
where c2 is not null
UNION ALL
SELECT id,c3 cv
 FROM t_col_row 
where c3 is not null;

8.下面可能是dba经常使用的oracle视图吧。呵呵

Sql代码

  1. 1.示例:已知hash_value:3111103299,查询sql语句:
  2. select*fromv$sqltext
  3. wherehashvalue='3111103299'
  4. orderbypiece
  5. 2.查看消耗资源最多的SQL:
  6. SELECThash_value,executions,buffer_gets,disk_reads,parse_calls
  7. FROMV$SQLAREA
  8. WHEREbuffer_gets>10000000ORdisk_reads>1000000
  9. ORDERBYbuffer_gets+100*disk_readsDESC;
  10. 3.查看某条SQL语句的资源消耗:
  11. SELECThash_value,parse_calls
  12. FROMV$SQLAREA
  13. WHEREhash_Value=228801498ANDaddress=hextoraw('CBD8E4B0');
  14. 4.查询sql语句的动态执行计划:
  15. 首先使用下面的语句找到语句的在执行计划中的address和hash_code
  16. SELECTsql_text,address,hash_valueFROMv$sqlt
  17. where(sql_textlike'%FUNCTION_T(表名大写!)%')
  18. 然后:
  19. SELECToperation,options,object_name,costFROMv$sql_plan
  20. WHEREaddress='C00000016BD6D248'ANDhash_value=664376056;
  21. 5.查询oracle的版本:
  22. select*fromv$version;
  23. 6.查询数据库的一些参数:
  24. select*fromv$parameter
  25. 7.查找你的session信息
  26. SELECTSID,OSUSER,USERNAME,MACHINE,PROCESS
  27. FROMV$SESSIONWHEREaudsid=userenv('SESSIONID');
  28. 8.当machine已知的情况下查找session
  29. SELECTSID,TERMINAL
  30. FROMV$SESSION
  31. WHEREterminal='pts/tl'ANDmachine='rgmdbs1';
  32. 9.查找当前被某个指定session正在运行的sql语句。假设sessionID为100
  33. selectb.sql_text
  34. fromv$sessiona,v$sqlareab
  35. wherea.sql_hashvalue=b.hash_valueanda.sid=100
1.示例:已知hash_value:3111103299,查询sql语句:
select * from v$sqltext 
where hashvalue='3111103299'
order by piece 
2.查看消耗资源最多的SQL:
SELECT hash_value,parse_calls
FROM V$SQLAREA
WHERE buffer_gets > 10000000OR disk_reads > 1000000
ORDERBY buffer_gets + 100 * disk_reads DESC;

3.查看某条SQL语句的资源消耗:
SELECT hash_value,parse_calls
FROM V$SQLAREA
WHERE hash_Value = 228801498AND address = hextoraw('CBD8E4B0');

4.查询sql语句的动态执行计划:
        首先使用下面的语句找到语句的在执行计划中的address和hash_code
        SELECT sql_text,hash_value FROM v$sql t
                where (sql_text like '%FUNCTION_T(表名大写!)%')
        然后:
        SELECT operation,cost FROM v$sql_plan
                WHERE address = 'C00000016BD6D248' AND hash_value = 664376056;

5.查询oracle的版本:
select * from v$version;

6.查询数据库的一些参数:
select * from v$parameter

7.查找你的session信息
SELECT SID,PROCESS
FROM V$SESSION WHERE audsid = userenv('SESSIONID');

8.当machine已知的情况下查找session
SELECT SID,TERMINAL
FROM V$SESSION
WHERE terminal = 'pts/tl' AND machine = 'rgmdbs1';

9.查找当前被某个指定session正在运行的sql语句。假设sessionID为100
select b.sql_text 
from v$session a,v$sqlarea b 
where a.sql_hashvalue=b.hash_value and a.sid=100

dawei

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