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Postgres vs MariaDB: Which Database Should You Use in 2026?

August 29, 2026 by Chat2DB Team

PostgreSQL and MariaDB are the two heavyweight open-source relational databases you can run anywhere without a licensing conversation. MariaDB began in 2009 as a community fork of MySQL (led by MySQL's original author) and stays wire-compatible with the MySQL ecosystem; PostgreSQL has evolved independently since the 1980s with a reputation for standards compliance and extensibility. They overlap enormously — both are fast, ACID-compliant, replicated, and battle-tested — so the decision comes down to specific capabilities and ecosystem fit. This comparison walks through the differences that actually change outcomes.

At a glance

SQL features and data types

This is where the gap is widest. PostgreSQL offers:

• Rich types: arrays, ranges, inet, uuid, composite types, and true jsonb with indexing:

-- Postgres: index a JSON attribute and query it
CREATE INDEX ON events USING gin (payload jsonb_path_ops);
SELECT * FROM events WHERE payload @> '{"type": "signup"}';

• Full window function and CTE support on both sides these days — MariaDB caught up on window functions and recursive CTEs in 10.2 — but PostgreSQL still goes further: FILTER aggregates, GROUPING SETS, LATERAL joins, DISTINCT ON, materialized views, and transactional DDL (roll back a failed migration mid-way — MariaDB's DDL is only partially atomic since 10.6, not transactional).
• Custom everything: operators, aggregate functions, index access methods. Extensions like PostGIS (geospatial), pgvector (embeddings), and TimescaleDB (time series) turn Postgres into several specialized databases at once.

MariaDB's counterpart strengths are pragmatic: INSERT ... ON DUPLICATE KEY UPDATE familiarity, generated columns, dynamic columns, and system-versioned tables (built-in temporal "AS OF" queries, which PostgreSQL only gets via extensions):

-- MariaDB: time-travel query on a system-versioned table
SELECT * FROM accounts FOR SYSTEM_TIME AS OF '2026-08-01 00:00:00';

Architecture: processes, engines, MVCC

Concurrency model. Both use MVCC, but differently. PostgreSQL keeps old row versions in the table itself and cleans them with VACUUM — write-heavy workloads need autovacuum attention (bloat, transaction ID management). InnoDB (MariaDB) keeps undo logs separately and generally needs less routine maintenance, but long-running transactions inflate undo/history length with similar practical effects.

Connections. PostgreSQL spawns a process per connection; thousands of connections want PgBouncer in front. MariaDB uses a thread per connection (plus a thread pool option), which tolerates high connection counts more gracefully out of the box.

Storage engines. MariaDB's pluggable engines are a genuine differentiator: ColumnStore for analytics, Spider for sharding, S3 engine for archival — chosen per table. PostgreSQL has one engine, tuned well, with table access methods slowly opening that door.

Query planner. PostgreSQL's optimizer handles complex joins, subqueries and mixed OLTP/analytical queries noticeably better; it's a common reason teams migrate analytics-leaning workloads off MySQL-family databases. For simple key-value style OLTP (fetch by PK, small updates), both are extremely fast and the difference rarely decides anything.

Replication and high availability

• MariaDB: classic async/semi-sync replication familiar to MySQL operators, plus Galera Cluster built in — virtually synchronous multi-primary clustering. Galera is MariaDB's HA ace: certified writes on all nodes, automatic membership handling.
• PostgreSQL: streaming physical replication (near-realtime standbys, synchronous if desired) and logical replication for selective/cross-version replication. Multi-primary is not native; HA is assembled with Patroni + etcd or managed by operators like CloudNativePG on Kubernetes — mature, but more moving pieces to own yourself.

If you need multi-primary writes with automatic failover and minimal assembly, Galera is a real argument for MariaDB. If you need selective replication, zero-downtime major upgrades, or CDC into Kafka (Debezium reads Postgres WAL cleanly), PostgreSQL's logical replication is the stronger base.

Performance characteristics

Honest answer: workload decides, benchmarks mislead. Credible generalizations:

• Simple read-heavy OLTP at high connection counts: MariaDB/InnoDB is excellent and forgiving.
• Complex joins, aggregations, window-function reporting on live data: PostgreSQL's planner usually wins.
• Write-heavy with long transactions: both need care (autovacuum tuning vs undo history); neither is a free lunch.
• Full-text search: PostgreSQL's tsvector/GIN is far more capable than MariaDB's FULLTEXT.

Run your own workload before believing any chart — and measure with realistic concurrency.

Ecosystem and operations

MariaDB inherits the enormous MySQL ecosystem (drivers, ORMs, DBA muscle memory) and is the default MySQL replacement in many Linux distributions. Caveat: MariaDB and MySQL have drifted — features and JSON internals differ, and "MySQL-compatible" no longer means identical (MariaDB 10.x/11.x vs MySQL 8.x are distinct dialects now).

PostgreSQL's ecosystem trend is hard to miss: it's the default choice of new SaaS platforms (Supabase, Neon), the base for serverless and vector-search offerings, and the most common answer in developer surveys for "database you want to work with." Extension availability (pgvector for AI workloads especially) is doing a lot of that work.

Both are fully supported by modern tooling. If your team works across both — say a legacy MariaDB app plus new Postgres services — a client that speaks both dialects saves real friction: Chat2DB (opens in a new tab) connects to PostgreSQL, MariaDB, MySQL and 20+ other engines in one UI, with AI that generates dialect-correct SQL for whichever connection you're on (also in-browser at app.chat2db.ai (opens in a new tab)).

Choose PostgreSQL when…

• Queries are complex: reporting, analytics on live data, many joins, window functions.
• You want jsonb, arrays, PostGIS, pgvector, or TimescaleDB — the extension ecosystem.
• Data integrity features matter: transactional DDL, deferrable constraints, exclusion constraints.
• You're building something new without MySQL-ecosystem constraints (most greenfield advice lands here).

Choose MariaDB when…

• You're replacing MySQL and want drop-in compatibility with existing apps, backups and skills.
• Galera-style multi-primary clustering out of the box is a requirement.
• Your workload is classic web OLTP with high connection counts and simple queries.
• You want per-table storage engines (columnar analytics via ColumnStore) inside one server.

FAQ

Is MariaDB faster than PostgreSQL? For simple primary-key OLTP, they're comparable, with MariaDB historically handling many raw connections more gracefully. For complex queries, PostgreSQL's planner usually produces better plans. Any blanket "X is faster" claim without your workload attached is marketing.

Can I migrate from MariaDB to PostgreSQL? Yes — pgloader automates schema and data conversion for the common cases, though stored procedures, dialect-specific SQL (ON DUPLICATE KEY UPDATE → ON CONFLICT), and implicit type coercions need hand-porting. See our MySQL-family to PostgreSQL conversion tool (opens in a new tab) for translating individual statements.

Is MariaDB still compatible with MySQL? Wire-protocol and mostly SQL-compatible, but no longer a drop-in for every feature: JSON handling, some replication internals, and newer SQL features differ between MariaDB 11.x and MySQL 8.x. Treat them as sibling dialects, not the same database.