What are the differences between mysql and oracle?

The differences between mysql and oracle are: 1. Oracle database is an object-relational database management system, which requires a fee; MySQL is an open source relational database management system, which is free; 2. The difference in database security; 3. Differences in object names; 4. Differences in temporary table processing methods, etc.

The operating environment of this article: Windows7 system, Dell G3 computer, Oracle version 9.0.1.1.2&&mysql8.

MySQL and Oracle are both popular relational database management systems (RDBMS) that are widely used around the world; most databases work in a similar way, but there are always some differences here and there between MySQL and Oracle . This article will compare Oracle and MySQL and introduce the differences between Oracle and MySQL. I hope it will be helpful to you.

What is the difference between MySQL and Oracle? The characteristics of the two databases are different, so compared with Oracle, MySQL is used differently; compared with MySQL, Oracle is used differently. Their characteristics are also different. Let's take a closer look at the differences between MySQL and Oracle.

1. The essential difference

Oracle database is an object-relational database management system (ORDBMS). It is often called Oracle RDBMS or simply Oracle and is a database.

MySQL is an open source relational database management system (RDBMS). It is the most used RDBMS in the world and runs as a server providing multi-user access to multiple databases. It is an open source, free database.

2. Database security

MySQL uses three parameters to authenticate users, namely username, password and location; Oracle uses many security features, such as username , passwords, profiles, local authentication, external authentication, advanced security enhancements, and more.

3. Differences in SQL syntax

Oracle’s SQL syntax is very different from MySQL. Oracle provides greater flexibility with a programming language called PL/SQL. Oracle's SQL*Plus tools provide more commands than MySQL for generating report output and variable definitions.

4. Storage differences:

Compared with Oracle, MySQL does not have table spaces, role management, snapshots, synonyms and packages, and automatic storage management.

5. Differences in object names:

Although some schema object names are not case-sensitive in Oracle and MySQL, such as columns, stored procedures, indexes, etc. . But in some cases, case sensitivity is different between the two databases.

Oracle is case-insensitive for all object names; while some MySQL object names (such as databases and tables) are case-sensitive (depending on the underlying operating system).

6. Running program and external program support:

Oracle database supports several programming languages ​​that are written, compiled and executed from within the database. Furthermore, to transfer data, Oracle Database uses XML.

MySQL does not support the execution of other languages ​​within the system, nor does it support XML.

7. Comparison of character data types between MySQL and Oracle:

There are some differences in the character types supported in the two databases. For character types, MySQL has CHAR and VARCHAR, with a maximum allowed length of 65,535 bytes (CHAR can be up to 255 bytes, VARCHAR is 65.535 bytes).

However, Oracle supports four character types, namely CHAR, NCHAR, VARCHAR2 and NVARCHAR2; all four character types need to be at least 1 byte long; CHAR and NCHAR can be up to 2000 bytes, NVARCHAR2 And the maximum limit of VARCHAR2 is 4000 bytes. Might be extended in the latest version.

8. Comparison of additional features between MySQL and Oracle:

MySQL database does not support any features on its server, such as Audit Vault. Oracle, on the other hand, supports several extensions and programs on its database servers, such as Active Data Guard, Audit Vault, Partitioning, and Data Mining, etc.

9. The difference between temporary tables:

Oracle and MySQL handle temporary tables in different ways.

In MySQL, temporary tables are database objects visible only to the current user session, and these tables are automatically deleted once the session ends.

The definition of temporary tables in Oracle is slightly different from MySQL in that temporary tables exist once they are created until they are explicitly dropped and are visible to all sessions with appropriate permissions. However, data in a temporary table is visible only to the user session that inserted the data into the table, and the data may persist across transactions or user sessions.

10. Backup types in MySQL and Oracle:

Oracle provides different types of backup tools, such as cold backup, hot backup, export, import, Data Pump. Oracle provides the most popular backup utility called Recovery Manager (RMAN). Using RMAN, we can automate our backup schedule and restore database using very few commands or storage scripts.

MySQL has mysqldump and mysqlhotcopy backup tools. There is no utility like RMAN in MySQL.

11. Database management of Oracle and MySQL:

In the database management part, Oracle DBA is more profitable than MySQL DBA. Oracle DBA has a lot of scope available compared to MySQL.

12. Database certification:

MySQL certification is easier than Oracle certification.

Unlike Oracle (when set up to use database authentication) and most other databases that only use username and password to authenticate users, MySQL uses additional parameters when authenticating users to location. This location parameter is usually a hostname, IP address, or wildcard.

Using this additional parameter, MySQL can further restrict user access to the database to specific hosts or hosts in the domain. Additionally, this allows different passwords and permission sets to be enforced for users based on the host from which they are connecting. Therefore, user scott logged in from abc.com may or may not be the same as user scott logged in from xyz.com.

Summary: The above is the entire content of this article, I hope it will be helpful to everyone's study.

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