MariaDB vs PostgreSQL: Architecture, Features, Performance and Which to Choose

The short answer

Choose MariaDB when your applications were written for MySQL, your team knows the MySQL toolchain, and you want built-in multi-primary clustering with Galera. Choose PostgreSQL for new applications that need richer SQL, transactional schema changes, indexed JSON, or extensions such as pgvector, and when you want the most permissive licence. Both are mature, open source relational databases. The deciding factors are compatibility with what you already run, the features your data model needs, and the high-availability design you want to operate.

MariaDB vs PostgreSQL at a glance

Licence and governance

MariaDB Server is licensed under GPLv2, and the MariaDB Foundation states it will remain free and open source software independent of any commercial entity; MariaDB Corporation is the main code contributor and sells products and services. PostgreSQL is released under the PostgreSQL License, a liberal licence similar to BSD or MIT, by the PostgreSQL Global Development Group, with no single company in control. For most users running either database internally, both licences are fine. The PostgreSQL License matters more if you embed and redistribute the database in a product.

Where they differ technically

Connections. PostgreSQL uses a process-per-user model: every client connection gets its own backend process. That isolates sessions well but makes a connection pooler or a driver-side pool standard practice for applications with many short connections. MariaDB handles connections with threads and has a dynamic, adaptive thread pool for high connection counts.

Schema changes. In MariaDB, DDL statements implicitly commit the current transaction before they run, even if they then fail. In PostgreSQL most DDL is transactional, so a migration that creates tables and alters columns can be rolled back as a unit if one step fails. For teams that ship schema migrations often, this is a practical safety difference.

JSON. MariaDB's JSON type is an alias for LONGTEXT with a binary collation, kept for MySQL compatibility, and JSON functions operate on the text. PostgreSQL's jsonb stores a decomposed binary form, supports GIN indexes for containment and key lookups, and is what PostgreSQL recommends for most applications.

Features MariaDB has that PostgreSQL handles differently. MariaDB ships system-versioned (temporal) tables, sequences, an Oracle compatibility mode, RETURNING clauses, MariaDB Vector, and pluggable storage engines such as ColumnStore for analytics and Spider for sharding. PostgreSQL covers similar ground through its core features and extensions, such as declarative partitioning, parallel query, many index types and pgvector for vectors.

High availability

MariaDB Galera Cluster is a virtually synchronous multi-primary cluster: any node can take reads and writes, it runs on Linux, and it supports the InnoDB engine only. Galera ships as a standard part of MariaDB Server. PostgreSQL ships streaming replication with read-only hot standbys and logical replication, but its documentation says it does not provide the software to detect a primary failure and promote a standby. Production PostgreSQL clusters add Patroni or repmgr for that; see Patroni vs repmgr.

MariaDB vs PostgreSQL performance

There is no general winner, and published benchmarks rarely match your schema. MariaDB's InnoDB stores rows in primary-key order, and its thread pool is built for many concurrent connections. PostgreSQL's planner, parallel query and index variety tend to help on complex joins, analytics and JSON queries. Both depend far more on indexes, configuration and hardware than on the engine. Test with your own queries and data volumes, and include vacuum in PostgreSQL and Galera certification in MariaDB in what you measure.

Release cycles and support

The MariaDB Foundation names one long-term support release a year. From 11.8, community LTS binaries are published for three years after GA, with critical and security fixes in source form for two more; releases up to 11.4 got five years. 12.3 is the newest LTS, with community support to 12 June 2029, and 10.6 left community maintenance on 6 July 2026. PostgreSQL supports each major version for five years: 18 is supported to 14 November 2030, and 14 reaches end of life on 12 November 2026.

MariaDB vs PostgreSQL vs MySQL and MongoDB

MariaDB began as a fork of MySQL and remains close to it, but the two have diverged: JSON storage, GTIDs and authentication defaults differ, and moving from MySQL 8.0 to MariaDB is a dump and reload rather than an in-place upgrade. Our MariaDB vs MySQL comparison covers that, and PostgreSQL vs MySQL covers the other pairing. Against MongoDB, both are relational databases with fixed schemas and joins; MongoDB stores documents with a flexible schema and is under the SSPL. If you are weighing documents against tables, start with MongoDB vs PostgreSQL.

How to choose

• Choose MariaDB if you are replacing MySQL 5.7 or earlier, depend on MySQL clients and tooling, want Galera multi-primary clustering out of the box, or need temporal tables or ColumnStore without adding another system.
• Choose PostgreSQL for new applications, complex SQL and reporting, indexed JSON, vector search through pgvector, transactional migrations, or a permissive licence for redistribution.
• Keep both if you already run both. The cost is operational knowledge rather than licences.

Where OSSeva fits

OSSeva supports both. OSSeva for MariaDB ships patched, signed builds of 10.4, 10.5 and 10.6 after community end of life and supports the 10.11, 11.4, 11.8 and 12.3 LTS lines; OSSeva Assure adds a Galera and replication topology review and a MySQL-to-MariaDB compatibility assessment. OSSeva for PostgreSQL patches 11, 12 and 13, and 14 after 12 November 2026, and OSSeva Operate monitors Patroni and repmgr clusters 24/7. For MariaDB, OSSeva Operate patches Critical CVEs (CVSS ≥ 9.0) within 48 hours and High within 7 days. Support starts on the community binaries you run today, with no migration first. Both are priced per cluster and sit under one contract with MySQL, Redis, Valkey and Kafka. Book a discovery call for a quote.

Frequently asked questions

MariaDB vs PostgreSQL: which is better?

For MySQL-compatible applications and multi-primary clustering, MariaDB. For new applications, complex SQL, indexed JSON and extensions, PostgreSQL. Neither is better in general; pick on compatibility and the features your data model needs.

MariaDB vs PostgreSQL performance: which is faster?

It depends on the workload. Simple primary-key reads and writes run well on both. PostgreSQL's planner and parallel query tend to help on complex queries; MariaDB's thread pool helps with very many connections. Benchmark with your own schema and queries.

MariaDB vs PostgreSQL vs MySQL: how do they relate?

MariaDB is a fork of MySQL and keeps its protocol and SQL dialect, though the two have diverged. PostgreSQL is a separate project with its own SQL dialect and tooling. Moving between MySQL and MariaDB is far easier than moving either to PostgreSQL.

MariaDB vs MongoDB: when does a document database make sense?

When your data is naturally a set of self-contained documents with varying fields and you rarely join across them. MariaDB can store JSON as text but does not index it as a native type; PostgreSQL's jsonb is the closer relational alternative to MongoDB.

Can I migrate from MariaDB to PostgreSQL?

Yes, with a schema conversion, a data load and application testing. AUTO_INCREMENT becomes identity columns, backtick quoting becomes double quotes, and MariaDB-specific SQL needs rewriting. Plan it as a migration project, with both databases supported during the parallel run.