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Postgres vs MySQL: Which MCP should you use?

🐘

Postgres

The world's most advanced open-source relational DB

VS
🐬

MySQL

Ubiquitous open-source relational DB

TL;DR

Both are mature open-source relational databases. Postgres has richer SQL (CTEs, window functions, JSON, arrays, extensions), stricter standards compliance, and better for complex analytics. MySQL is simpler, often faster on basic read-heavy workloads, and dominates WordPress/PHP ecosystems.

Postgres: 4 winsMySQL: 2 wins2 ties
🐘

Pick Postgres

Pick Postgres when you need complex queries, JSON handling, GIS, or extensions like pgvector.

🐬

Pick MySQL

Pick MySQL when you run a LAMP stack, need simpler ops, or use PlanetScale/Vitess for sharding.

Feature-by-feature comparison

SQL standard compliance

A

Postgres

High

MySQL

Moderate

JSON support

A

Postgres

JSONB with indexing

MySQL

JSON (less mature)

Extensions

A

Postgres

pgvector, PostGIS, TimescaleDB

MySQL

Limited

Replication

Tie

Postgres

Logical + streaming

MySQL

Binlog, row-based

Read performance (simple)

B

Postgres

Good

MySQL

Often faster

Write performance (heavy)

A

Postgres

Excellent

MySQL

Good

Horizontal scaling

B

Postgres

Citus / Spanner-compat

MySQL

Vitess (PlanetScale)

Ecosystem

Tie

Postgres

Rich for analytics/AI

MySQL

Rich for web/CMS

🐘

Best for

Postgres

  • SQL standard compliance: High
  • JSON support: JSONB with indexing
  • Extensions: pgvector, PostGIS, TimescaleDB
  • Write performance (heavy): Excellent
🐬

Best for

MySQL

  • Read performance (simple): Often faster
  • Horizontal scaling: Vitess (PlanetScale)

Migration path

Use pgloader for MySQL→Postgres — it handles schema, data, and most type mappings (watch TINYINT(1) → BOOLEAN). Postgres→MySQL is harder: no arrays, no CHECK constraints historically, different sequence semantics. Rewrite queries that use RETURNING, ILIKE, or schema-qualified names.

Frequently asked questions

What is the main difference between Postgres and MySQL?

Both are mature open-source relational databases. Postgres has richer SQL (CTEs, window functions, JSON, arrays, extensions), stricter standards compliance, and better for complex analytics. MySQL is simpler, often faster on basic read-heavy workloads, and dominates WordPress/PHP ecosystems. In short: Postgres — The world's most advanced open-source relational DB. MySQL — Ubiquitous open-source relational DB.

When should I pick Postgres over MySQL?

Pick Postgres when you need complex queries, JSON handling, GIS, or extensions like pgvector.

When should I pick MySQL over Postgres?

Pick MySQL when you run a LAMP stack, need simpler ops, or use PlanetScale/Vitess for sharding.

Can I migrate from one to the other?

Use pgloader for MySQL→Postgres — it handles schema, data, and most type mappings (watch TINYINT(1) → BOOLEAN). Postgres→MySQL is harder: no arrays, no CHECK constraints historically, different sequence semantics. Rewrite queries that use RETURNING, ILIKE, or schema-qualified names.

Do Postgres and MySQL both work with MCP-compatible AI agents?

Yes. Both have MCP servers installable via MCPizy (mcpizy install postgres and mcpizy install mysql). They work identically across Claude Code, Claude Desktop, Cursor, Windsurf, and any other MCP-compatible client. You can install both side by side and route queries in your agent's prompt.

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🟢VS🔥

Supabase vs Firebase

Both are BaaS offerings. Supabase is Postgres-based (relational, SQL, open-source), Firebase is Firestore-based (NoSQL, proprietary, Google Cloud). Supabase wins if you want SQL, lower lock-in, and predictable pricing. Firebase wins for mobile-first apps tied to Google's ecosystem.

🍃VS🐘

MongoDB vs Postgres

MongoDB is a document database — flexible schemas, built-in sharding, great for unstructured data and rapid prototyping. Postgres is relational but its JSONB type covers most 'flexible schema' use-cases while also giving you joins, transactions, and stricter integrity.

Install both with MCPizy

Not sure? Run both side by side — swap between them in your AI agent with a single config line.

$mcpizy install postgres && mcpizy install mysql
🐘Install Postgres🐬Install MySQL
Free to install. Swap between them in your agent config.