Oracle Study Notes: sqlplus User Logon

Oracle Study Notes: sqlplus User Logon

1 sqlplus Login

Local login (log on to the database server)

Oracle Logon

Sqlplus account name/password as role name

1.1 sys Login

Example: sqlplus sys/oracle

ERROR:

ORA-28009: connection as SYS shocould be as SYSDBA or SYSOPER

The sys administrator must have the sysdba role.

[Oracle @ yutianedu ~] $ Sqlplus sys/oracle as sysdba

Execute show user;

SQL> show user; displays the current Login user

USER is "SYS"

Exit

1.2 system Logon

Sqlplus system/oracle

1.3 scott login (representative of common Users)

By default, normal users are locked and cannot log on.

You can use the Administrator to unlock and the administrator can reset the password.

1.3.1 Administrator Logon

Sqlplus sys/oracle as sysdba

1.3.2 unlock and reset the password

Alter user scott account unlock; unlock

Alter user scott identified by oracle; Set scott's password to oracle

1.3.3 scott Login

Sqlpous scott/oracle

Question 1: Is it possible that one server has multiple databases?

Which one does sqlplus sys/oracle as sysdba log on ??????

When you log on, you will check the environment variable ORACLE_SID to indicate which instance you are logged on.

How to view the value of an environment variable currently in effect

[Oracle @ yutianedu ~] $ Env | grep ORACLE_SID

If you do not specify the default logon, it should be an orcl instance.

Summary: templates for local logon in the future

Install Oracle 11gR2 (x64) in CentOS 6.4)

Steps for installing Oracle 11gR2 in vmwarevm

Install Oracle 11g XE R2 In Debian

First define the instance you want to log on ---> export ORACLE_SID = orcl

Then log on to ---> sqlplus sys/oracle as sysdba

Question 2: Did I enter the password at login and who will verify the password?

Sys is the operating system verification and database is irrelevant

You can log on to the database no matter whether the database is started or not.

What IS OS verification? First, log on to the operating system. Then, if you have the permission to log on, the password is not verified.

Oracle logon --- oracle belongs to the dba group ---- You have sysdba Permissions

Sqlplus/as sysdba; Password Authentication Not Required

SQL> show user;

USER is "SYS"

Common users use data dictionary verification.

A data dictionary is a table in a database that stores account and password information.

If the database is not started to the open state, it is not allowed to read the database of tables in the database.

If a common user logs on, the database must be in the open

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