Oracle different users

Oracle is a relational database management system, which can be managed and operated by different users. Different users have different rights and roles, so that the security and flexibility of the database can be controlled. This article will introduce the classification, authority and application of different users in Oracle.

First, user classification

Users in Oracle can be divided into two categories: system users and ordinary users.

1. System users

System users are users created by default to manage the database. SYSTEM users include SYS and System. The former has the rights of data dictionary and system management, while the latter has the rights of system management, database creation, backup and recovery. These two kinds of users can only operate under SYSDBA authority.

2. Ordinary users

Ordinary users are users created by administrators for database applications. Ordinary users are divided into two types: connected users and owner users.

① Connected users are users who connect to the database through their user names and passwords, and can only operate the objects they own. Because the connected user has only basic operation rights, it will not affect other users and objects. There are a wide range of usage scenarios, such as users when an application connects to a database.

② The owner user is the user who created the database object by the administrator, who owns the object and can perform all operations on it. Owner users can create tables, views, indexes, stored procedures, triggers, sequences and other objects. Because the owner user has high authority, it needs the administrator to strictly authorize and manage it.

Second, the user rights

User rights in Oracle can be divided into system rights and object rights.

1. System permissions

System permissions refer to the ability to operate the whole database at the system level, such as defining users, creating tables, backing up and restoring, and modifying the database. SYSTEM privileges can be granted to users through system privileged roles, including SELECT ANY TABLE, CREATE TABLE, DROP ANY TABLE, system, DBA, etc.

2. Object permissions

Object permissions refer to permissions that can operate on specific objects, including reading and writing operations, modifying and deleting objects such as tables, views and sequences. Object permissions can only be authorized by the object owner user.

Third, user applications

User applications in Oracle can be divided into two categories: basic operations and advanced operations.

1. Basic operation

The basic operation is to perform simple operations such as INSERT, SELECT, UPDATE and DELETE through SQL statements. These operations are mainly aimed at table objects, and they are operated by connecting users. For example, use SELECT to query the table and use INSERT to insert the table.

2. Advanced operation

Advanced operations are mainly based on objects and PL/SQL language, including stored procedures, triggers, sequences and so on. These operations are mainly aimed at the owner user, which requires the owner user to have higher authority. For example, triggers are used to implement data integrity constraints, and stored procedures are used for data processing and business logic processing.

conclusion

By introducing the classification, authority and application of different users of Oracle, we can find that user management of Oracle provides a balance between flexibility and security. Administrators can create appropriate users, roles and permissions, so as to realize the safe management and efficient application of the database. Therefore, when applying Oracle database, it is necessary to properly manage users, so as to realize high-quality data processing and reasonable data security control.