Why Choose MySQL Over PostgreSQL? Key Technical Drawbacks Explained

Domestic PostgreSQL‑based systems

TBase (Tencent) – https://github.com/Tencent/TBase – integrates GTM global transaction manager for cross‑shard transactions.

PolarDB for PostgreSQL (Alibaba) – redesigns storage to enable shared‑read and second‑scale read‑replica expansion.

GaussDB (openGauss) (Huawei) – adds a columnar engine and AI optimizer to support HTAP workloads.

openHalo (Hangzhou Yijing) –

https://github.com/HaloTech-Co-Ltd/openHalo

Technical gaps of MySQL that drive migration to PostgreSQL

Limited native data types

MySQL core types are basic; PostgreSQL provides ARRAY, range types such as int4range and tsrange, composite types (e.g., POINT(x,y)), and JSONB with indexing and efficient queries.

Absence of a true independent sequence object

MySQL 5.7+ simulates SEQUENCE with AUTO_INCREMENT plus an offset (e.g., 3088413) that is bound to a table. PostgreSQL creates a standalone sequence:

-- PostgreSQL independent sequence
CREATE SEQUENCE order_seq START WITH 1 INCREMENT BY 1;

INSERT INTO orders (id, name) VALUES (nextval('order_seq'), 'test');

In MySQL the same requires ALTER TABLE … AUTO_INCREMENT or a user variable, which cannot be shared across tables and is error‑prone in distributed environments.

Extensibility ecosystem

PostgreSQL extensions used in production: TimescaleDB – time‑series database with automatic partitioning and compression. pg_trgm – fuzzy matching and similarity search. Citus – distributed database extension. pg_stat_statements – SQL execution statistics.

MySQL’s comparable ecosystem is considerably smaller.

Performance‑monitoring tools

PostgreSQL ships built‑in views such as pg_stat_activity, pg_stat_statements, pg_locks and supports EXPLAIN ANALYZE for real execution metrics.

Third‑party tools (PgAdmin, pg_stat_monitor, Prometheus + Grafana) provide visual execution plans and lock graphs.

MySQL relies on Performance Schema and slow_query_log, which require complex configuration; diagnosis often falls back to manual SHOW PROCESSLIST and EXPLAIN.

Replication and consistency

MySQL defaults to asynchronous replication, offers GTID (which can break if mis‑configured) and optional semi‑sync that needs extra setup and high‑quality network. It lacks built‑in strong consistency guarantees; primary failure may cause lost transactions.

PostgreSQL provides:

Streaming Replication with selectable async or sync mode.

Logical Replication for table‑level or cross‑version data movement.

Mature Write‑Ahead Logging (WAL) ensuring durability.

Synchronous Replication where the primary waits for at least one replica acknowledgment, achieving zero data loss.

MVCC implementation differences

PostgreSQL’s MVCC allows readers to see a previous snapshot while writers are active.

MySQL’s default isolation can expose dirty reads or non‑repeatable reads depending on the chosen level.

Conclusion

Choosing PostgreSQL or MySQL depends on system requirements: PostgreSQL offers richer data modeling, independent sequences, a robust extension framework, integrated monitoring, and strong consistency suitable for long‑term evolution and complex workloads; MySQL remains efficient for read‑heavy, fast‑to‑market web applications. The rise of domestic databases in China builds on PostgreSQL’s technical advantages to achieve independent innovation.