Postgres vs MySQL vs MariaDB: A 2026 Decision Guide for Builders

"Which database should we use?" is one of the rare technical questions where the answer in 2026 is: any of them is probably fine. PostgreSQL, MySQL, and MariaDB have all converged on a feature set that covers 95% of what most products need. The interesting differences are subtler than the internet typically suggests.

What's actually identical

Stop comparing on these — all three are equivalent enough not to matter for a typical product:

• Transactions, foreign keys, indexes, joins. Same standards, same correctness.
• Read performance for typical OLTP queries. Indistinguishable on a 100k-row table; indistinguishable on a 100m-row table with proper indexes.
• Backup and replication primitives. All three have battle-tested logical and physical replication.

What's actually different

JSON, arrays, and complex types

Postgres has the most expressive type system: native JSONB with full GIN indexing, arrays, ranges, custom types, and PostGIS. MySQL 8 and MariaDB 11 both have JSON now but with slightly weaker indexing semantics. If your data model has fields like "user preferences" or "feature flags" stored as documents inside a row, Postgres wins by a comfortable margin.

Full-text search

Postgres' built-in full-text search is good enough for most applications and supports stemming, ranking, and trigram fuzzy matching. MySQL's InnoDB FULLTEXT works but with fewer knobs. If you need real search you'll outgrow either eventually and move to OpenSearch / Meilisearch / Typesense — the database choice doesn't really change that.

Concurrency model

Postgres uses MVCC with each transaction getting a snapshot. Long-running read transactions can cause table bloat that requires periodic VACUUM tuning. MySQL/MariaDB also use MVCC but with a different undo-log mechanism that has different failure modes. For most teams under 1 TB of data, neither matters; past that, you'll be tuning whichever you picked.

Hosted offerings

This is the most under-discussed but practically important factor:

• AWS RDS supports all three; Aurora has a Postgres flavour and a MySQL flavour with serverless and multi-region options.
• Google Cloud SQL supports Postgres and MySQL; AlloyDB is a Postgres-only managed service with built-in caching.
• Azure Database for MySQL/PostgreSQL exists; MariaDB is being deprecated.
• Smaller managed providers (Neon, Supabase, PlanetScale) tend to specialise. Neon and Supabase are Postgres-only; PlanetScale is MySQL.

If you might want to use a serverless Postgres provider one day, you have a structural reason to pick Postgres now.

MariaDB's specific position

MariaDB is an excellent drop-in for MySQL workloads, especially for small teams who want a single-vendor relationship. We use it ourselves at eDarpan because it ships with sensible defaults, has predictable upgrade paths, and runs anywhere MySQL runs. The downside is that the cloud-managed offerings are thinner — Azure has been retreating, and AWS RDS still calls it "MariaDB" but has not invested in it the way it has in Postgres.

When MariaDB is right

• You'll self-host or use a small managed provider in your home region.
• Your application is comfortable on standard MySQL semantics.
• You want a database that is genuinely community-governed.

The honest recommendation

If you have no strong preference and no existing tooling, default to Postgres. The combination of richer types, the strongest cloud offerings, and the deepest tooling (drizzle-orm, prisma, sqlc, pgcat, all the connection poolers) makes it the path of least resistance for the next decade.

If you have an existing MySQL operational footprint or your team's muscle memory is in MySQL, MySQL or MariaDB is fine. Don't switch for status reasons; switch only if you have a concrete feature gap you keep hitting.

The wrong move is to spend three weeks "comparing databases" before writing your first migration. Pick one in an afternoon, write the schema, ship features. The choice will rarely be the thing that determines whether your product wins.