密码文件的恢复 || EM登录失败的解决
1，密码文件默认位置是：/u01/oracle/product/10.2.0/db_1/dbs/orapwSID
如果密码文件被损坏，则无法远程登录，em无法登录，会出现，“username or password invalid”的错误。
2，这时可以重新创建密码文件：
cd /u01/oracle/product/10.2.0/db_1/dbs
orapwd file=orapwdv11 password=oracle entries=5 force=y
3，查看密码文件：
SQL> select * from v$pwfile_users;
USERNAME SYSDB SYSOP
------------------------------ ----- -----
SYS TRUE TRUE
[oracle@redhat dbs]$ strings orapwdv11
]\[Z
ORACLE Remote Password file
INTERNAL
AB27B53EDC5FEF41
8A8F025737A9097A
SYSTEM
2D594E86F93B17A1
4，对system赋sysoper权限，则system的信息就会被写入密码文件：
SQL> grant sysoper to system;
Grant succeeded.
SQL> select * from v$pwfile_users;
USERNAME SYSDB SYSOP
------------------------------ ----- -----
SYS TRUE TRUE
SYSTEM FALSE TRUE
5，sys与sysoper权限的不同之处：
SQL> select * from system_privilege_map where name like '%SYS%';
PRIVILEGE NAME PROPERTY
---------- ---------------------------------------- ----------
-3 ALTER SYSTEM 0
-4 AUDIT SYSTEM 0
-83 SYSDBA 0
-84 SYSOPER 0
When you connect with SYSDBA or SYSOPER privileges, you connect with a default schema,
not with the schema that is generally associated with your username.
For SYSDBA this schema is SYS; for SYSOPER the schema is PUBLIC
SQL> conn / as sysdba
SQL> show user
USER is "SYS"
SQL> conn / as sysoper
Connected.
SQL> show user
USER is "PUBLIC"
6，密码认证类型：
SQL> show parameter remote_login_passwordfile
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
remote_login_passwordfile string EXCLUSIVE
remote_login_passwordfile = none | exclusive |shared 位于$ORACLE_HOME/dbs/spfile$ORACLE_SID.ora参数文件中
none : 不使用密码文件认证
exclusive :要密码文件认证，自己独占使用(默认值)
shared ：要密码文件认证，不同实例dba用户可以共享密码文件
-------------------------------------------------------------------
useful scripts：
alter user system identified by oracle;
alter user scott account unlock;
grant sysdba to system;
show parameter pfile
show parameter spfile
show parameter remote_login_passwordfile
desc v$pwfile_users;
select * from v$pwfile_users;
cd /u01/oracle/product/10.2.0/db_1/dbs
orapwd file=orapwdv11 password=oracle entries=5 force=y
strings orapwdv11
SQL> select * from v$pwfile_users;
USERNAME SYSDB SYSOP
------------------------------ ----- --
---
SYS TRUE TRUE
SQL> grant sysoper to system;
Grant succeeded.
SQL> select * from v$pwfile_users;
USERNAME SYSDB SYSOP
------------------------------ ----- -----
SYS TRUE TRUE
SYSTEM FALSE TRUE
When you connect with SYSDBA or SYSOPER privileges, you connect with a default schema,
not with the schema that is generally associated with your username.
For SYSDBA this schema is SYS; for SYSOPER the schema is PUBLIC
SQL> select * from system_privilege_map where name like '%SYS%';
PRIVILEGE NAME PROPERTY
---------- ---------------------------------------- ----------
-3 ALTER SYSTEM 0
-4 AUDIT SYSTEM 0
-83 SYSDBA 0
-84 SYSOPER 0
SQL> show user
USER is "SYS"
SQL> conn / as sysoper
Connected.
SQL> show user
USER is "PUBLIC"
