Let's talk about the methods and precautions for modifying the SYS user in Oracle

The SYS user in the Oracle database is the account with the highest authority and has control over the entire database. Therefore, under normal circumstances, it is not recommended to modify the SYS user. But sometimes in order to solve specific problems, it may be necessary to modify the default settings of the SYS user.

This article will introduce some methods and precautions for modifying SYS users.

1. Change the SYS user password

The SYS user is the most important user in the Oracle database, and the password setting should be strong. If you forget the password of the SYS user or need to change the password, you can do it through the following methods:

First, log in to the Oracle database with SYSDBA permissions:

$ sqlplus '/as sysdba'

Then, use the following command to modify the SYS user password:

SQL> ALTER USER SYS IDENTIFIED BY "new_password";

"new_password" is the value of the new password, enclosed in quotation marks.

2. Modify the SYS user default table space

In the Oracle database, each user has a default table space, which stores all tables and indexes created by the user. etc. objects. The default tablespace for the SYS user is SYSTEM. If you need to change the default table space of the SYS user to another table space, you can use the following method:

First, log in to the Oracle database with SYSDBA permissions:

$ sqlplus '/as sysdba'

Then, use the following command to modify the SYS user default tablespace:

SQL> ALTER USER SYS DEFAULT TABLESPACE "new_tablespace";

"new_tablespace" is the name of the new tablespace, use enclosed in quotation marks.

3. Modify the SYS user temporary table space

In the Oracle database, each user has a default temporary table space, which stores all temporary tables created by the user. etc. objects. The default temporary tablespace for the SYS user is TEMP. If you need to change the default temporary table space of the SYS user to another table space, you can use the following method:

First, log in to the Oracle database with SYSDBA permissions:

$ sqlplus '/as sysdba'

Then, use the following command to modify the SYS user default temporary tablespace:

SQL> ALTER USER SYS TEMPORARY TABLESPACE "new_temp_tablespace";

"new_temp_tablespace" is the new temporary tablespace Name, enclosed in quotes.

Note: Modifying the SYS user's default table space and default temporary table space may affect system performance, so you should choose carefully.

4. Modify other attributes of the SYS user

Other attributes of the SYS user can also be modified, such as: limiting the login time of the SYS user and setting failed login attempts for the SYS user times, set the password expiration time of the SYS user, etc.

Similarly, log in to the Oracle database with SYSDBA permissions and execute the following statement to modify the SYS user attributes:

SQL> ALTER USER SYS ACCOUNT LOCK;

This command will prohibit the SYS user from logging in .

SQL> ALTER PROFILE DEFAULT LIMIT FAILED_LOGIN_ATTEMPTS 3;

This command sets the maximum number of failed login attempts for the SYS user to 3.

SQL> ALTER PROFILE DEFAULT LIMIT PASSWORD_LIFE_TIME 90;

This command sets the password validity period of the SYS user to 90 days.

Note: Changing these properties may affect the security and stability of the system. You should make modifications while ensuring that you are aware of the risks and impacts of the operation.

Summary

Changing the default settings for the SYS user is uncommon, but in some extreme cases, it may be necessary. The above introduces several methods to modify the SYS user, including modifying the password, default table space, default temporary table space and other attributes. You need to choose according to the specific conditions of your own system to ensure the security and stability of the operation.

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