I‘m Klaus Aschenbrenner, a Microsoft Certified Master for SQL Server
» I help people to bring their SQL Server & PostgreSQL
installations to a new level of excellence. «
SQLpassion Offerings
SQLpassion helps businesses get the most out of SQL Server & PostgreSQL – from smooth setups to better performance and long-term stability. As a Microsoft Certified Master, I offer tailored consulting, hands-on workshops, and share my expertise at international events – all with a clear focus on delivering real results.
Read one of my latest blog posts:
The Linux Page Cache and PostgreSQL
PostgreSQL performance on Linux is often discussed in terms of SQL tuning, indexes, and query plans. Yet many real-world performance problems originate much lower in the stack: inside the Linux page cache and its writeback policy. PostgreSQL deliberately relies on the kernel for file caching and writeback, which means that kernel misconfiguration can silently undermine
Where is My Clustered Index in PostgreSQL?
Every SQL Server professional eventually reaches a point where storage internals stop being abstract. You learn that a table is not just a logical container but a physical structure, and that structure is defined by the clustered index. Rows live at the leaf level of a B-tree, the clustering key defines physical order, and every
Vector Capabilities with pgvector in PostgreSQL
With SQL Server 2025, Microsoft introduces vector support as a native engine feature: a built-in VECTOR(dim) data type, dedicated vector functions, and an approximate vector index tightly integrated into the optimizer. From a SQL Server point of view, this feels natural—vectors become another first-class datatype, queried via explicit functions such as VECTOR_DISTANCE or VECTOR_SEARCH, and
Watch one of my latest YouTube videos:
Introducing my new PostgreSQL Quickies Series on YouTube
For many years I have been publishing my SQL Server Quickies – short, focused videos that explain specific database topics in just a few minutes. These quick sessions have helped countless developers and DBAs to sharpen their skills without the need to spend hours in front of lengthy tutorials. Now it’s time to expand this concept into
Online Recording: Exploring PostgreSQL for SQL Server Developers and DBAs
On January 9 I have done an online presentation about Exploring PostgreSQL for the SQL Server Developers and DBAs for the Cloud Data Driven User Group. You can find the recording of the whole session (around 105 minutes) here to watch: If you’d like to explore the differences between SQL Server and PostgreSQL in greater depth,
SQL Server Quickie #48 – Azure SQL Managed Instance
Today I have uploaded SQL Server Quickie #48 to YouTube. This time I’m talking about Azure SQL Managed Instance. If you are interested in learning more about this very interestingh topic, I highly recommend to check-out my live training about it that I run from November 27 – 28, 2024.
