MariaDB and MySQL are two relational databases sharing the same foundation. In 2009 Oracle acquired MySQL, and MySQL's founder Michael "Monty" Widenius forked MariaDB to keep the open-source MySQL alive. Today they're developed separately, but many features remain compatible.
Main differences
Storage engines โ MySQL: InnoDB (main), MyISAM, MEMORY. MariaDB has more: InnoDB, Aria (a MyISAM replacement), TokuDB (large volumes), ColumnStore (analytics), MyRocks (Facebook-developed, high compression).
Query cache โ MySQL 8.0 removed it (concurrent-connection issues), MariaDB still supports it. Useful for small and mid-size sites.
JSON functions โ MySQL 5.7+ and MariaDB 10.2+ both support JSON, but syntax differs slightly. Be careful when writing code.
Spatial (GIS) functions โ available in both, but MariaDB is more optimized.
License โ MySQL is under Oracle control with dual licensing (free open-source and commercial). MariaDB is fully open-source under GPL v2; the company cannot close the source.
Performance comparison
On simple SELECT, INSERT, UPDATE, the two are roughly equivalent (5-10% difference depending on case). MariaDB with the Aria storage engine can run 2-3x faster on some workloads. For JSON and aggregation queries MySQL is slightly faster. Real-world: a WordPress site runs the same on both.
Migration between the two
Migration between MariaDB and MySQL is nearly safe โ datafiles and schemas are compatible. But new features in one aren't in the other โ going from a recent MariaDB back to an older MySQL can be tricky. cPanel typically uses MariaDB, but switching to MySQL is also possible.
Which to choose
Choose MariaDB when: open source matters to you; reseller hosting (most panels default to MariaDB); WordPress and PHP CMS projects; you need the Aria storage engine.
Choose MySQL when: you're in the Oracle ecosystem (integration with other Oracle products); MySQL Enterprise services are required; you need the latest JSON and analytic functions; more local developers know MySQL.
Sayt.uz practice
Sayt.uz hosting plans default to MariaDB (versions 10.5 and 10.6). 95% of clients don't notice the difference โ WordPress and other CMSes run identically on both. Clients needing MySQL can configure it on VPS or dedicated server tariffs. Tip: for small and mid-size projects MariaDB is slightly cheaper and safer on the licensing side. For large enterprise MySQL can be a marginally better choice.