MySQL vs PostgreSQL: Choosing Your Weapon in the 2009 Database Wars

It has been a chaotic month for the open-source community. With Oracle announcing their acquisition of Sun Microsystems just weeks ago, every SysAdmin running a LAMP stack is nervously watching the mailing lists. Is MySQL still safe? Should we all be migrating to PostgreSQL?

I’ve spent the last week migrating a high-traffic e-commerce client from a crumbling shared host in Germany to our dedicated infrastructure in Oslo. We saw queries hanging for 30 seconds on simple joins. The culprit wasn't just the hardware; it was the wrong database engine choice. This debate isn't about philosophy anymore—it's about uptime, latency, and keeping your pager quiet at 3:00 AM.

The Speed Demon: MySQL 5.1

MySQL is the default for a reason. It powers Facebook and Wikipedia. It is fast, familiar, and the replication is simple enough that a junior admin can set up a Master-Slave configuration in an hour.

However, many of you are still relying on the default MyISAM storage engine. Stop doing this. MyISAM uses table-level locking. If you have a heavy write-load (like a busy forum or a logging system), one write locks the entire table, queuing up all read requests. Your load average spikes, and your site stalls.

Pro Tip for CoolVDS Users: If you are running MySQL on our Xen VPS nodes, switch your tables to InnoDB. It provides row-level locking and crash recovery. Add this to your /etc/my.cnf to safeguard your data:

innodb_flush_log_at_trx_commit = 2
(Sacrifices 1 second of ACID compliance for a massive speed boost).

The Tank: PostgreSQL 8.3

If MySQL is a Corvette, PostgreSQL is a Panzer tank. It adheres strictly to SQL standards and doesn't cut corners on data integrity. With version 8.3, we finally got the performance improvements we needed, specifically with HOT (Heap-Only Tuples) updates, which drastically reduces the need for the dreaded VACUUM operations.

PostgreSQL shines where MySQL stumbles: complex queries. If your application relies on sub-selects, complex joins, or geographical data (PostGIS is years ahead of MySQL's spatial extensions), Postgres is the only professional choice.

The "War Story" Scenario

Last year, I managed a project for a Norwegian logistics firm tracking shipments across Europe. We started with MySQL. As the dataset grew to 10GB, our reporting queries (involving 5-way joins) started taking 15 seconds. We couldn't cache our way out of it.

We migrated to PostgreSQL 8.3. The same query, optimized with the correct indices, dropped to 400ms. No hardware change. Pure architectural efficiency.

Infrastructure Matters: The I/O Bottleneck

Regardless of your database choice, your database is only as fast as the disk it sits on. Most VPS providers oversell their I/O. They put you on a crowded node with 50 other clients fighting for the same hard drive arm. When your neighbor runs a backup script, your database latency spikes.

This is where the physical layer hits reality. At CoolVDS, we don't play the "burst RAM" game. We use enterprise-grade 15k RPM SAS RAID-10 arrays and are currently testing the new Intel X25-E Enterprise SSDs for our high-performance tier. Low latency is critical, especially here in Norway.

Latency to NIX (Norwegian Internet Exchange)

Hosting your database in the US or even Germany adds 30-100ms of latency to every round trip. If your PHP application makes 10 database calls to generate a page, that's a full second of delay before the user sees anything. Hosting locally in Oslo keeps that latency under 5ms.

Comparison: When to Use Which?

The Compliance Angle: Datatilsynet is Watching

We cannot ignore the legal reality. The Data Inspectorate (Datatilsynet) enforces the Personal Data Act (Personopplysningsloven) strictly. Hosting customer data on US servers (subject to the Patriot Act) is becoming a liability for Norwegian businesses. Keeping your database on a Norwegian VPS isn't just about speed; it's about sovereignty.

Final Verdict

If you are running a standard Joomla or WordPress site, stick with MySQL. It's optimized for simple reads and is easy to manage.

If you are building a custom application with complex data relationships or require absolute data integrity, PostgreSQL is the superior engineering choice.

But remember: a tuned database on a choked disk is useless. Don't let IO wait times kill your application's performance.

Need to test your schema performance? Deploy a CoolVDS Xen instance with high-speed SAS storage in Oslo today. We guarantee dedicated resources, so your benchmarks actually mean something.