PostgreSQL vs MySQL - Which Database for Your SaaS

PostgreSQL vs MySQL for a SaaS has a clear default in 2026: choose PostgreSQL. It offers JSONB with indexing, richer data types, MVCC concurrency, and a deep extension ecosystem including full-text search. MySQL is still excellent and battle-tested — but Postgres gives a growing SaaS more headroom without switching databases later. Here's the honest comparison.

Quick Answer

For most new SaaS apps, choose PostgreSQL: richer data types (JSONB, arrays), strong concurrency via MVCC, and a deep extension ecosystem (full-text search, PostGIS). Choose MySQL if your team already knows it well or you depend on a MySQL-only managed service. Both are reliable, ACID-compliant relational databases — Postgres simply gives a growing app more headroom.

The short difference

PostgreSQL leans feature-rich and standards-driven; MySQL leans simple and very widely hosted. Both store relational data with SQL and ACID transactions, so either will serve a typical SaaS. The decision is about features and ecosystem, not reliability.

At a glance

(Engine features evolve — verify version specifics before committing.)

Data types and JSON

Postgres offers JSONB (binary JSON you can index and query efficiently), arrays, and custom types, which is handy when your schema mixes relational and semi-structured data. MySQL has a JSON type too, but Postgres's JSONB is generally more powerful.

Concurrency and writes

Postgres uses MVCC (multi-version concurrency control) for strong read/write concurrency without heavy locking. MySQL's behavior depends on the storage engine (InnoDB is the default and is solid). For write-heavy, concurrent workloads, Postgres is a safe default.

Extensions and search

Postgres's extension ecosystem — full-text search, PostGIS for geo, and many more — lets you add capabilities without bolting on another system. This is a common reason teams pick Postgres for a product they expect to grow.

When MySQL is the better pick

If your team is already fluent in MySQL, or your hosting/managed service is MySQL-first, the productivity of familiarity can outweigh Postgres's feature edge. MySQL remains a great, battle-tested database.

Which to choose for a SaaS?

• Choose PostgreSQL if: you want the richest features and room to grow (the default for most new SaaS).

• Choose MySQL if: your team or stack is already MySQL-centric.

How this maps to FastStaq

FastStaq uses PostgreSQL via Prisma as its database, with a migrations workflow in server/prisma/migrations/ and the schema in server/prisma/schema.prisma. That is our pick for the headroom described above — but MySQL is a fine choice for teams already invested in it. See how to use Supabase with Next.js and Supabase vs plain PostgreSQL.

Frequently asked questions

Is PostgreSQL better than MySQL? For most new SaaS apps, Postgres's richer features and concurrency make it the better default; MySQL is excellent when your team knows it.

Can I switch later? It is possible but non-trivial — choosing well up front saves a migration. An ORM like Prisma eases some of the work.

Which does FastStaq use? PostgreSQL via Prisma.

Next steps

• Read how to use Supabase with Next.js

• See Supabase vs plain PostgreSQL

• Compare Neon vs Supabase

• Read the best database for a SaaS