From MySQL to PostgreSQL: a much lighter server
I recently migrated mpazari.com, a Turkish motorcycle classifieds site, from MySQL 8 to PostgreSQL 12. The application is a Spring Boot 4 / Java 25 GraalVM native image using hand-written SQL. The migration involved moving the existing database, adapting the MySQL-specific queries, and testing the application against a real production snapshot. The migration was completed with approximately three minutes of downtime. The main steps were: Create the PostgreSQL schema. Copy the MySQL data into PostgreSQL. Update the application queries for PostgreSQL. Run the test suite and verify the row counts. Stop the application, perform the final copy, switch the JDBC URL, and restart it. PostgreSQL’s stricter typing exposed a few old data and SQL issues that MySQL had silently accepted. The test suite helped find and fix those issues before the production cutover. ...