Welcome to Özkan Pakdil’s Blog

👋 Hello! I’m Özkan Pakdil, a software engineer with professional experience since 2004.

  • I specialize in Java development and C# but consider myself a full-stack developer with expertise in backend, database, server-side development, UI, and UX.

  • My technical journey spans various technologies including Spring Boot, Kubernetes, React, and many more. I’m a Linux enthusiast since 1999 and enjoy optimizing system performance.

  • This blog contains articles about technologies I use and my experiences in software development. Feel free to explore my projects on GitHub.

Enterprise SSL certificate creation for PostgreSQL PKI design

Enterprise SSL Certificate Creation for PostgreSQL: From Development to Production

When implementing secure PostgreSQL connections, certificate creation forms the foundation of your PKI infrastructure. Whether you’re setting up a development environment or deploying enterprise-grade systems, understanding proper certificate creation practices is crucial. This guide explores certificate creation from the simple OpenSSL approach to enterprise-grade practices employed by major financial institutions like Credit Suisse/UBS and media companies like BBC. Related Reading: For implementing DN-based certificate authentication in PostgreSQL, see our DN Authentication guide. ...

August 15, 2025 · 7 min · Özkan Pakdil
PostgreSQL DN Distinguished Name certificate authentication design

PostgreSQL Distinguished Name (DN) Authentication: Beyond CN-Based Certificate Mapping

Today, I’m diving into Distinguished Name (DN) authentication—a powerful feature that enables certificate-based authentication when the Common Name (CN) in your client certificate doesn’t match your PostgreSQL username. This approach is essential in enterprise environments where certificate naming conventions don’t align with database user naming requirements. Version Compatibility: The clientname=DN feature was introduced in PostgreSQL 14. If you’re using PostgreSQL 13 or earlier versions, this DN authentication method will not work and you’ll need to use traditional CN-based certificate authentication instead. ...

August 15, 2025 · 8 min · Özkan Pakdil
Postgresql mtls SAN subject alternative names design

Designing mTLS for PostgreSQL: Getting SAN and Hostname Verification Right

Mutual TLS (mTLS) for PostgreSQL provides strong, passwordless authentication and encryption. The most common cause of failed secure connections in real deployments is incorrect Subject Alternative Name (SAN) handling and trust configuration on the client side. This post explains how to set up SANs correctly, how hostname verification really works, and how to align PostgreSQL with enterprise PKI practices—using this repository’s cluster as a concrete example. Why SAN Matters More Than CN Modern TLS stacks validate the server’s identity against the SAN extension on the server certificate—not the Common Name (CN). When a PostgreSQL client connects to a host name (or IP), it will check: ...

August 14, 2025 · 7 min · Özkan Pakdil
Pagination Pitfall Cover

The Pagination Pitfall: A React + Spring Boot Cautionary Tale

🚀 The Pagination Pitfall: A React + Spring Boot Cautionary Tale The Setup: “It’ll Be Fine…” A few years ago, I was working on a dashboard application with a React frontend and a Spring Boot backend. The task seemed simple: display a list of users with pagination. One of the newer devs suggested: “Let’s just fetch everything once and paginate on the client side — it’ll be faster for the user.” ...

August 7, 2025 · 3 min · Özkan Pakdil

🔍 Ways to Monitor PostgreSQL Queries (Concise Overview)

1. pg_stat_statements Extension that tracks execution statistics for all SQL statements (execution count, total time, etc.). Here full docs 2. PostgreSQL Logging (postgresql.conf) Configure parameters like log_statement, log_duration, or log_min_duration_statement to log queries to a file. 3. auto_explain Automatically logs execution plans for slow queries, useful for performance tuning. 4. pg_stat_activity View currently running queries and session info: SELECT * FROM pg_stat_activity; 5. pgBadger A powerful log analyzer that generates detailed HTML reports from PostgreSQL logs. ...

July 15, 2025 · 1 min · Özkan Pakdil