Note: This article is from: The Linux community Guoliang "Oracle Learning Note: Sqlplus User Login "
1 Sqlplus Log on locally (log on to the database server)
Oracle Login sqlplus account name/password as role name 1.1 SYS login
For example:
1 sqlplus sys/oracle
ERROR:
Ora-28009:connection as SYS should be as SYSDBA or sysoper
SYS administrator must have role sysdba
1 [[email protected] ~]$ Sqlplus sys/oracle as Sysdba
Execute show user;
Sql> Show user; Show currently logged on user
USER is "SYS"
Exit exit
1.2 System Login
Sqlplus system/oracle
1.3 Scott Login (on behalf of ordinary users)
Default normal user is locked not allowed to login
Can be unlocked with the administrator, the administrator can reset the password
1.3.1 Administrator Login
Sqlplus Sys/oracle as Sysdba
1.3.2 Unlock Reset Password
Alter user Scott account unlock; Unlock
Alter user Scott identified by Oracle; Set Scott's password to be Oracle
1.3.3 Scott Login
Sqlpous scott/oracle
Question 1: Is it possible that a server has multiple databases
Sqlplus Sys/oracle as SYSDBA which one is logged in??????
When you log in, you will see the environment variable ORACLE_SID indicates which instance you are logged into
How to view a value with an environment variable that is currently in effect
[Email protected] ~]$ env |grep ORACLE_SID
If you do not specify a default login should be an ORCL instance
Summary: Later locally logged-on templates
Install Oracle 11gR2 (x64) http://www.linuxidc.com/Linux/2014-02/97374.htm under CentOS 6.4
Oracle 11gR2 installation steps in VMware virtual machines http://www.linuxidc.com/Linux/2013-09/89579p2.htm
Install Oracle 11g XE R2 http://www.linuxidc.com/Linux/2014-03/98881.htm under Debian
First define the instance you want to log into---> Export ORACLE_SID=ORCL
Then sign in---> Sqlplus sys/oracle as Sysdba
Question 2: When logged in is not entered the password, who verifies the password
SYS is operating system validation and database is not related
The database can be logged on either starting or not starting the administrator
What is operating system validation? Log in to the operating system first and then as long as you have permission to login, not verify password
Oracle Login---Oracle belongs to DBA Group----SYSDBA Permissions
Sqlplus/as sysdba; no password Authentication required
Sql> Show user;
USER is "SYS"
Data dictionary validation is used by ordinary users
A data dictionary is a table in a database that stores account and password information
If the database does not boot to the open state, the database is not allowed to read tables in the database
If a normal user is logged in, you must first ensure that the database is open
Sqlplus User Login