PostgreSQL for MySQL Developers: A Practical Guide to the Differences

If you've spent years working with MySQL, PostgreSQL doesn't feel like a completely different database.

The SQL is familiar. Your application architecture can remain familiar. Most basic queries look familiar.

The surprises come from the details.

PostgreSQL is stricter about types and identifier handling, uses different syntax for several everyday operations, and exposes database capabilities that don't have direct MySQL equivalents.

A few examples:

• AUTO_INCREMENT becomes an identity column or SERIAL

• ON DUPLICATE KEY UPDATE becomes ON CONFLICT

• LIKE and ILIKE have different semantics

• TINYINT(1) is commonly replaced by a real BOOLEAN

• JSONB provides indexed document storage with operators that go beyond basic JSON extraction

• Partial and expression indexes allow much more targeted indexing strategies

• DDL can participate in transactions

• PostgreSQL's connection model makes pooling an important production consideration

The more interesting part is that not every migration problem produces an error.

A query can execute successfully and still behave differently.

Case-insensitive searches are one example. MySQL's default collation can make LIKE behave differently from PostgreSQL, where LIKE is case-sensitive and ILIKE is the explicit case-insensitive option.

There are also operational differences worth understanding before production. PostgreSQL's MVCC implementation creates dead tuples that autovacuum needs to reclaim. Large production indexes may require CREATE INDEX CONCURRENTLY. Applications using stricter isolation levels may need retry logic.

And then there are the PostgreSQL features that can change how you design your application, such as JSONB with GIN indexes, native arrays, row-level security, partial indexes, and transactional schema changes.

The goal of this guide isn't to declare one database better than the other. It's to give MySQL developers a practical map of what changes when they start writing PostgreSQL.

The full article walks through the syntax, data types, query differences, indexing strategies, transactions, production gotchas, and includes a MySQL-to-PostgreSQL quick-reference cheat sheet.

Read the complete guide here:

https://devencyclopedia.com/blog/postgresql-for-mysql-developers