转载请注明出处: http://renjie120.iteye.com/
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.查看所有用户:
- select*fromdba_user;
- select*fromall_users;
- select*fromuser_users;
- 2.查看用户系统权限:
- select*fromdba_sys_privs;
- select*fromall_sys_privs;
- select*fromuser_sys_privs;
- 3.查看用户对象权限:
- select*fromdba_tab_privs;
- select*fromall_tab_privs;
- select*fromuser_tab_privs;
- 4.查看所有角色:
- select*fromdba_roles;
- 5.查看用户所拥有的角色:
- select*fromdba_role_privs;
- 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.查询oracle中所有用户信息
- select*fromdba_user;
- 2.只查询用户和密码
- selectusername,passwordfromdba_users;
- 3.查询当前用户信息
- select*fromdba_ustats;
- 4.查询用户可以访问的视图文本
- select*fromdba_varrays;
- 5.查询数据库中所有视图的文本
- select*fromdba_views;
- 6.查询全部索引
- select*fromuser_indexes;
- 查询全部表格
- select*fromuser_tables;
- 查询全部约束
- select*fromuser_constraints;
- 查询全部对象
- 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).查看相关进程在数据库中的会话
- Selecta.sid,a.serial#,a.program,a.status,
- substr(a.machine,1,20),a.terminal,b.spid
- fromv$sessiona,v$processb
- wherea.paddr=b.addr
- andb.spid=&spid;
- (2).查看数据库中被锁住的对象和相关会话
- selecta.sid,a.username,
- c.owner,c.object_name
- fromv$sessiona,v$locked_objectb,all_objectsc
- wherea.sid=b.session_idand
- c.object_id=b.object_id;
- (3).查看相关会话正在执行的SQL
- selectsql_textfromv$sqlareawhereaddress=
- (selectsql_addressfromv$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
- 建立一个例子表:
- CREATETABLEt_col_row(
- IDINT,
- c1VARCHAR2(10),
- c2VARCHAR2(10),
- c3VARCHAR2(10));
- INSERTINTOt_col_rowVALUES(1,’v11′,’v21′,’v31′);
- INSERTINTOt_col_rowVALUES(2,’v12′,’v22′,NULL);
- INSERTINTOt_col_rowVALUES(3,’v13′,NULL,’v33′);
- INSERTINTOt_col_rowVALUES(4,’v24′,’v34′);
- INSERTINTOt_col_rowVALUES(5,’v15′,NULL);
- INSERTINTOt_col_rowVALUES(6,’v35′);
- INSERTINTOt_col_rowVALUES(7,NULL);
- COMMIT;
- 下面的是列转行:创建了一个视图
- CREATEviewv_row_colAS
- SELECTid,’c1’cn,c1cv
- FROMt_col_row
- UNIONALL
- SELECTid,’c2’cn,c2cv
- FROMt_col_row
- UNIONALL
- SELECTid,’c3’cn,c3cvFROMt_col_row;
- 下面是创建了没有空值的一个竖表:
- CREATEviewv_row_col_notnullAS
- SELECTid,c1cv
- FROMt_col_row
- wherec1isnotnull
- UNIONALL
- SELECTid,c2cv
- FROMt_col_row
- wherec2isnotnull
- UNIONALL
- SELECTid,c3cv
- FROMt_col_row
- 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.示例:已知hash_value:3111103299,查询sql语句:
- select*fromv$sqltext
- wherehashvalue=’3111103299′
- orderbypiece
- 2.查看消耗资源最多的SQL:
- SELECThash_value,executions,buffer_gets,disk_reads,parse_calls
- FROMV$SQLAREA
- WHEREbuffer_gets>10000000ORdisk_reads>1000000
- ORDERBYbuffer_gets+100*disk_readsDESC;
- 3.查看某条SQL语句的资源消耗:
- SELECThash_value,parse_calls
- FROMV$SQLAREA
- WHEREhash_Value=228801498ANDaddress=hextoraw(‘CBD8E4B0’);
- 4.查询sql语句的动态执行计划:
- 首先使用下面的语句找到语句的在执行计划中的address和hash_code
- SELECTsql_text,address,hash_valueFROMv$sqlt
- where(sql_textlike’%FUNCTION_T(表名大写!)%’)
- 然后:
- SELECToperation,options,object_name,costFROMv$sql_plan
- WHEREaddress=’C00000016BD6D248’ANDhash_value=664376056;
- 5.查询oracle的版本:
- select*fromv$version;
- 6.查询数据库的一些参数:
- select*fromv$parameter
- 7.查找你的session信息
- SELECTSID,OSUSER,USERNAME,MACHINE,PROCESS
- FROMV$SESSIONWHEREaudsid=userenv(‘SESSIONID’);
- 8.当machine已知的情况下查找session
- SELECTSID,TERMINAL
- FROMV$SESSION
- WHEREterminal=’pts/tl’ANDmachine=’rgmdbs1′;
- 9.查找当前被某个指定session正在运行的sql语句。假设sessionID为100
- selectb.sql_text
- fromv$sessiona,v$sqlareab
- wherea.sql_hashvalue=b.hash_valueanda.sid=100
1.示例:已知hash_value:3111103299,查询sql语句: select * from v$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