A data blog, written at the foot of the Beskidy mountains.

Data is the Way.

I write about Databricks, AI, Fabric and SQL Server: what's new, what works in practice and what only looks good in a demo. I run the code from every post myself before publishing it.

What's new Fresh posts

An autumn ridge of the Beskidy mountains at golden hour, with a path through the grass in the foreground

DatabricksLakeflow · Unity Catalog · Delta

AIRAG · agents · ML

Fabricfirst posts in the works

SQL ServerSQL Server 2025 · vectors · T-SQL

DatabricksLakehouse, Lakeflow, Unity Catalog and everything in between.

AIRAG, agents, ML and evaluation. No magic, just measurement.

FabricFabric posts are in the works. They'll show up once they've been through the lab.

SQL ServerSQL Server 2025, vectors, search and good old T-SQL.

What's new.

Platform changes worth knowing about before you run into them on a project. Short, and with what they mean for you.

deprecationDBFS is gone from new workspaces. What changes on September 30, 2026From September 30, 2026, every new workspace is created without the DBFS root, mounts and Hive Metastore. Existing ones keep working, but it makes sense to move to Volumes and Unity Catalog now.Databricks6 min✓ tested in the lab 29 Sep 2026

Fresh posts.

All posts

Sketch: a notebook, Genie, an agent and BI all hit the row filter and column mask in the catalog

AI8 min✓ tested in the lab 29 Sep 2026Policies go to the catalog, not the prompt

The sentence “don’t show tax_id” in Genie instructions is not a safeguard. It is a request to the model.

SQL Server6 min✓ tested in the lab 29 Sep 2026Magnifying glass, book and buddy: LIKE, full-text and vectors in plain words

Databricks11 min✓ tested in the lab 29 Sep 2026Data skew in Spark: a decision tree

AI11 min✓ tested in the lab 29 Sep 2026Six layers of agent defence, and none of them is “the model refused”

SQL Server6 min✓ tested in the lab 29 Sep 2026SQL isn’t dying, it’s mutating

Databricks6 min✓ tested in the lab 29 Sep 2026DBFS is gone from new workspaces. What changes on September 30, 2026 and how to prepare

Krzysztof Burejza on a mountain trail, a rocky path into the sun behind him

About me.

I’m Krzysztof. I’ve been building data platforms for over 10 years, and I started with SQL Server, so I remember when “cloud” was something from the weather forecast.

I work mostly with Databricks, Microsoft Fabric and AI. I run training courses and workshops, speak at conferences and meetups, and in Bielsko-Biała I co-organise the Data Community Podbeskidzie group. Along the way I’ve picked up a few Databricks and Microsoft certifications, including Microsoft Certified Trainer.

This is where I write down what I’ve tested in practice, including what didn’t work.