MySQL vs PostgreSQL: Overview, Performance Comparison, and Use Cases

1. Database Introduction TLDR;

1.1 MySQL

MySQL claims to be the most popular open‑source database and is one of the leading relational database management systems (RDBMS). It is the "M" in the LAMP stack, and applications built on LAMP typically use MySQL.

MySQL was originally developed by MySQL AB, sold to Sun in 2008 for $1 billion, and then acquired by Oracle in 2010. Oracle now offers a commercial edition and a community edition; the latter is criticized because Oracle controls its development.

1.2 PostgreSQL

PostgreSQL positions itself as the most advanced open‑source database, belonging to the object‑relational DBMS (ORDBMS) family. It originated from the POSTGRES project at UC Berkeley in 1985 and is now a fully community‑driven open‑source project.

Unlike MySQL, PostgreSQL provides a single, complete feature set under a permissive BSD/MIT license, allowing organizations to use, copy, modify, and redistribute the code with only a copyright notice.

Note: MySQL hierarchy: instance → database → table PostgreSQL hierarchy: instance → database → schema → table A schema can be understood as a namespace and does not affect usage.

2. Performance Comparison

Test Environment

MySQL:

Hardware: 4‑core CPU, 16 GB RAM

Version: MySQL 8.0

PostgreSQL:

Hardware: 4‑core CPU, 16 GB RAM

Version: PostgreSQL 13

The benchmark used primary‑key SELECT, primary‑key UPDATE, and single‑row INSERT operations. The results lead to several conclusions:

In throughput, PostgreSQL outperforms MySQL by roughly 2× on SELECT, 4–5× on INSERT, and 5–6× on UPDATE.

Average latency shows PostgreSQL is several times faster than MySQL.

For hot‑row updates, MySQL achieves only about 1/8 of PostgreSQL's performance, with latency up to 7× higher.

3. Suitable Scenarios and How to Choose

MySQL is simpler and therefore more popular; it enjoys richer documentation and ecosystem support, making it a good choice for small‑to‑medium enterprises or personal projects where ease of use matters.

But this does not mean MySQL is the best choice.

PostgreSQL’s momentum is rapidly catching up with MySQL, while MySQL’s popularity shows a gradual decline.

MySQL Use Cases

MySQL suits simple applications such as e‑commerce sites, blogs, and general websites. It can handle data volumes from millions to hundreds of millions of rows, but under high‑performance demands (fast response, high throughput) it may become a bottleneck, especially with complex queries.

PostgreSQL Use Cases

PostgreSQL excels with complex data structures, advanced applications, and large‑scale datasets. It also works for smaller datasets, but its optimizer may occasionally choose sub‑optimal indexes for very complex query conditions.

4. Summary

Advantages of PostgreSQL over MySQL

Significantly better performance in both latency and overall throughput.

Superior single‑row update speed, especially with HOT UPDATE, offering an order‑of‑magnitude improvement.

More complete and rigorous SQL standard implementation.

Uses heap tables for primary storage, allowing larger data volumes than MySQL’s index‑organized tables.

Physical replication provides stronger data consistency and higher replication performance compared to MySQL’s binlog‑based logical replication.

PostgreSQL’s default repeatable read isolation level includes a hidden optimistic‑lock version column, delivering both correctness and performance, whereas MySQL’s repeatable read requires explicit locking or custom optimistic‑lock logic.

Disadvantages of PostgreSQL compared to MySQL

System catalog design is more complex, making certain administrative tasks harder.

Index selection can be trickier; PostgreSQL lacks MySQL’s convenient force_index hint.

Requires periodic VACUUM maintenance, which must be tuned for specific workloads.