MariaDB vs PostgreSQL (2026): Which Database Fits Your App?

This is for developers and sysadmins picking a relational database for something new, or wondering whether to leave a MySQL-style stack behind. Both of these are open source and both speak SQL, so the decision really comes down to two things: where your existing code already lives, and how unusual the data is that you need to model. Get those straight and most of the arguments you'll read online stop mattering. If your current stack grew up around MySQL, that history counts for more than it first seems, so be honest about how much of it you'd be rewriting.

Different family trees, so a move is a migration

This is the bit that catches teams out. MariaDB comes from the people who originally wrote MySQL, and it set out to be an improved stand-in that drops straight into MySQL's place. Postgres comes from somewhere else entirely: it began back in 1986 as POSTGRES, a University of California project at Berkeley.

So these aren't two versions of the same product. Moving from one to the other is a migration, with schema changes, query rewrites and a round of testing, not an upgrade you run on a quiet Sunday night. If your team talks about them as interchangeable, it's worth reading how MariaDB relates to MySQL first, because that's the family it was built to replace and the one it stays closest to.

Let hosting and tooling have a vote

Your hosting can make the first decision for you, so check what your host provides before you design anything. If you're on a platform where you choose and run your own database, you have a free hand, and the decision can rest on what your application needs. A plan built around an extension your host won't let you install ends in a rewrite.

Tooling matters too. Admin panels, backup scripts, monitoring and the framework your developers use all have opinions about which database they talk to. Popular frameworks tend to cover both, but plugins and older libraries sometimes don't. List the pieces that touch your database and check each one before you commit, not after.

How they compare

Point	MariaDB	PostgreSQL
Roots	MySQL's original authors	Berkeley, 1986
Built as	MySQL stand-in	Object-relational SQL
Open source	Promised to stay so	Yes
Extending	Engines, plugins	Custom types, add-ons
Documents	JSON	JSON/JSONB, Hstore and more
Location data	GIS	PostGIS
ACID	Unstated	Since 2001

When the MySQL stand-in is the easier call

If your application was written for MySQL, or your stack is already built around it, this side keeps life simple. Its whole reason for existing was to slot in where MySQL already sits, so your existing queries, drivers and admin habits should mostly carry over with little drama. That counts for a lot when a team is busy and the database isn't the interesting part of the product.

The engine-and-plugin ecosystem is the other draw. Its own page points to a wide choice of storage engines and plugins, which suits teams who like to pick the pieces around their data. And because its makers guarantee it'll stay open source, that suits teams who want the commitment in writing before they build on it for years.

When Postgres earns the switch

Pick it when your data doesn't fit neatly into rows of text and numbers. You can create data types and functions of your own, and its document options include JSON/JSONB and key-value Hstore. If you'd otherwise bolt a second database on purely for documents, that's worth a long look, because one system is nearly always easier to run than two.

Location work is another trigger. PostGIS, its geospatial add-on, is the one to look at when maps come up. And it's been ACID-compliant since 2001, which matters if correctness under load is the thing that keeps you awake at night.

What the two share

Both are open source, both use SQL, and both now handle JSON and geographic data in some form. For a plain web app with users, orders and sessions, either will do the job well. The differences show up at the edges: unusual data types, extensions, and the lineage of the code you already have sitting in production.

That overlap is worth remembering when someone on your team argues passionately for one side. For most ordinary applications, the database you can run well beats the database that wins on paper. Skills, monitoring and tested backups decide far more bad nights than feature lists ever do, so weigh your team's experience at least as heavily as anything in the table above.

Questions to settle before you migrate

• Does your app lean on MySQL-specific syntax?
• Do you need custom types or PostGIS?
• Which storage engines do you rely on today?
• Who will run it, and what tools do they know?

Mistakes that make a move hurt

The classic one is treating the switch as a weekend job. Data types don't map one to one, functions are named differently, and queries that leaned on one engine's quirks will behave differently on the other. The second is moving everything at once: move one service, or even one report, then watch it for a few weeks. The third is forgetting the people. Whoever gets called at night needs to be comfortable with the new system before it holds anything that matters, so training and a written runbook are part of the migration, not extras.

Whichever you pick, you'll probably live with it for years. That's a good reason to choose for the data you expect to hold in two years' time, not only the data you have today. If maps, documents or custom types are on the roadmap, factor them in now; if the roadmap is more of the same, the familiar option is rarely a bad call.

My suggestion: prototype the awkward query first

Don't decide from a feature list. Take the one query or data shape that makes your current setup creak, and build it on both.

1. Pick the hardest table or report in your app.
2. Stand up both databases locally with identical sample data.
3. Write that query on each, using whatever features help.
4. Note which needed fewer workarounds and read more clearly.
5. Plan the move starting with a read-only copy.

If you're still unsure where Postgres sits against the other big names, compare it with MySQL as well, since that's often the real choice hiding behind this one and the answer tends to carry across.

Frequently asked questions

Can MariaDB replace PostgreSQL as a drop-in?

No. It was designed as a drop-in replacement for MySQL, so leaving Postgres for it means a migration, not a swap.

Is MariaDB ACID-compliant?

Its own page doesn't make the claim, so check its documentation before you rely on it.

Does PostgreSQL support XML?

Yes. XML is on its own list of document data types.

Can MariaDB use a different storage engine per table?

Its page talks about a rich ecosystem of engines and plugins but doesn't spell out how they're assigned, so check its documentation for the detail.

Does MariaDB give you an SQL interface?

Yes, its own page says the server provides one, and that its latest versions include GIS and JSON features.

Can PostgreSQL store key-value data?

Yes, through Hstore. It's worth a look when you only need simple pairs of keys and values next to ordinary tables, rather than a second store to run.