MySQL vs PostgreSQL: Choosing the Right Engine for High-Traffic Norwegian Workloads

It is 3:00 AM on a Tuesday. My phone buzzes. It’s not a text from a friend; it’s a Nagios alert. The database load average on a client's e-commerce server just hit 20.0, and the site is timing out. Why? Because a backup script triggered a table lock on a 4GB MyISAM table, bringing the entire checkout process to a grinding halt.

If you have managed servers for more than a week, you know this pain. The choice between MySQL and PostgreSQL isn't just about syntax preference; it is about data integrity, locking mechanisms, and whether you sleep through the night. With the recent release of PostgreSQL 9.0 just last month and the ubiquity of MySQL 5.1, the landscape is shifting. Let’s look at the hard truths of running these databases on production VPS infrastructure in Norway.

The Default Giant: MySQL 5.1

MySQL is the engine of the web. It powers WordPress, Drupal, and Joomla. It is fast for reads and incredibly simple to set up. But in 2010, the default configuration is a trap.

The MyISAM Trap

By default, many MySQL installations still lean heavily on the MyISAM storage engine. MyISAM is fast for simple SELECT statements, but it uses table-level locking. If you update one row, the entire table is locked. On a high-traffic news site or forum, this leads to a backlog of queries that can melt your CPU.

The Fix: InnoDB. You must switch to InnoDB for row-level locking and transactions (ACID compliance). If you are running a serious application on CoolVDS, we recommend bypassing the defaults and tuning your my.cnf immediately to leverage the InnoDB Plugin.

[mysqld]
# Crucial for performance. Set to 70-80% of available RAM on a dedicated VPS.
innodb_buffer_pool_size = 2G

# Prevents the doublewrite buffer overhead if you trust your filesystem (risky but fast)
# innodb_doublewrite = 0

# Set this to 1 for full ACID compliance, or 2 if you can tolerate losing 1 second of data for speed
innodb_flush_log_at_trx_commit = 1

# Use per-table tablespaces for better disk management
innodb_file_per_table = 1

The Challenger: PostgreSQL 9.0

PostgreSQL has always been the "academic" choice—strict, reliable, and historically slower. That ends now. Version 9.0 (released September 2010) is a massive leap forward. It introduces Hot Standby and Streaming Replication built-in. Previously, setting up replication required hacky solutions like Slony-I or Pgpool-II. Now, it is native.

If your application deals with complex financial data, strict schema enforcement, or you are experimenting with spatial data via PostGIS, PostgreSQL is superior. It doesn't just store data; it validates it.

Configuration for Speed

Postgres defaults are notoriously conservative to ensure it runs on ancient hardware. On a modern CoolVDS slice with high-speed SAS storage, you need to open the throttle in postgresql.conf.

# PostgreSQL handles memory differently than MySQL. 
# Start with 25% of RAM for shared_buffers.
shared_buffers = 512M

# Effective cache size helps the planner estimate memory available for disk caching.
effective_cache_size = 1536M

# Checkpoints can cause I/O spikes. Smooth them out.
checkpoint_segments = 32
checkpoint_completion_target = 0.9

# Logging slow queries is mandatory for debugging
log_min_duration_statement = 250ms

War Story: The "Unexpected" Latency

Last year, we migrated a large Norwegian media portal from a shared hosting environment to a Dedicated VPS. They were using MySQL with complex JOINs. The site was sluggish. We ran EXPLAIN on their queries and realized MySQL's query optimizer was choosing full table scans over indexes.

We tested a migration to PostgreSQL. The Postgres query planner is significantly smarter about complex joins. Without changing the hardware, query execution time dropped from 1.2 seconds to 45ms. However, the migration wasn't free—rewriting SQL to be standard-compliant (MySQL is very forgiving with sloppy SQL) took two weeks.

Pro Tip: Data privacy is getting stricter here in Norway. Under the Personopplysningsloven (Personal Data Act of 2000), you are responsible for securing user data. PostgreSQL's robust role-based access control (RBAC) and SSL support make it easier to satisfy Datatilsynet requirements than a default MySQL install.

The Hardware Factor: I/O is the Bottleneck

Whether you choose MySQL or Postgres, your database is only as fast as the disk it sits on. In a virtualized environment, "Disk I/O Wait" is the silent killer. Many providers oversell their storage, putting fifty clients on a single SATA array. When one neighbor runs a backup, your database stalls.

At CoolVDS, we approach this differently:

• Virtualization: We use KVM (Kernel-based Virtual Machine) or Xen. Unlike OpenVZ, this provides better isolation. Your RAM is your RAM.
• Storage: We utilize Enterprise 15k RPM SAS drives in RAID 10 arrays, and we are rolling out Solid State Drive (SSD) tiering for high-performance instances. The latency difference is shocking—SSDs can handle thousands of IOPS compared to the ~150 IOPS of a standard drive.
• Network: With servers located directly in Oslo, latency to the Norwegian Internet Exchange (NIX) is often under 2ms.

Verdict: Which One to Pick?

If you are running a standard LAMP stack application like WordPress, MySQL 5.1 with InnoDB is the pragmatic choice. It is well-understood and supported by every tool on the market.

However, if you are building a custom application where data integrity is paramount, or you need advanced indexing (like partial indexes or functional indexes), PostgreSQL 9.0 is the superior engineering decision. The new replication features in 9.0 finally make it viable for high-availability setups without third-party tools.

Regardless of your engine, don't let slow shared hosting kill your performance. Database queries need low latency and high IOPS.

Ready to test your schema? Deploy a KVM instance on CoolVDS today and experience the difference of dedicated resources and low-latency Norwegian connectivity.