MariaDB: Comprehensive Overview
1. Introduction to MariaDB:
- MariaDB is an open-source relational database management system (RDBMS) and a fork of MySQL.
- Developed by the original creators of MySQL, including Michael "Monty" Widenius.
2. Key Features:
- Open Source: MariaDB is released under the GNU General Public License.
- Compatibility: Maintains compatibility with MySQL, making it a drop-in replacement.
- Performance: Optimized for high-performance and scalability.
- Security: Implements security features like user roles, encryption, and SSL/TLS support.
- Storage Engines: Supports various storage engines, including InnoDB and Aria.
- Community and Enterprise Editions: Offers a free community edition and a commercial enterprise edition.
3. Basic Concepts:
- Database: Container for tables and other objects.
- Table: Collection of rows and columns to store data.
- Column: Represents a single attribute in a table.
- Row: A record containing a set of values.
4. Data Types:
- Supports a wide range of data types, including integers, floating-point numbers, strings, and dates.
5. SQL Language Support:
- MariaDB uses SQL (Structured Query Language) for database manipulation.
- Supports standard SQL syntax with additional features and extensions.
6. Storage Engines:
- InnoDB: Default storage engine for ACID compliance and transactions.
- Aria: A storage engine for non-transactional tables with simplicity and speed.
- MyISAM: Offers fast read operations but lacks transaction support.
7. Replication:
- Supports master-slave replication for data redundancy and high availability.
8. Security:
- User Authentication: Supports user authentication with password-based and external authentication methods.
- SSL/TLS Encryption: Provides encryption for secure data transmission over the network.
9. High Availability:
- Supports solutions for high availability, including clustering and Galera Cluster.
10. Compatibility with MySQL:
- Designed to be a compatible drop-in replacement for MySQL.
- Allows migration from MySQL to MariaDB with minimal changes.
11. Use Cases:
- Web Applications: Suitable for web-based applications with its fast performance and scalability.
- Enterprise Solutions: Used in various enterprise-level applications for reliable data management.
- Data Warehousing: Handles large datasets efficiently for analytics and reporting.
12. Community and Support:
- MariaDB has an active open-source community that contributes to its development.
- Offers commercial support for enterprises through MariaDB Corporation.
13. Fork of MySQL:
- MariaDB was created as a fork of MySQL due to concerns about Oracle's acquisition of MySQL by Sun Microsystems.
14. Cloud Integration:
- Supports integration with cloud platforms and services, including Amazon RDS and Google Cloud SQL.
15. Licensing:
- Released under the GNU General Public License (GPL).
MariaDB is a robust, open-source relational database system that emphasizes performance, scalability, and compatibility with MySQL. Its feature-rich nature and active community make it a popular choice for a wide range of applications and industries.
how use variable column
ReplyDeletei try this
select idp,@jx:=sum(jmlh) as j1,@jx as j2 from bhutang
group by idp limit 5
result
1 56798310 430178580.318182
2 77274406.1818182 430178580.318182
3 904593505.363636 430178580.318182
4 12183685.4 430178580.318182
5 430178580.318182 430178580.318182
why j1 <> j2