Ever wondered why you can create tables in a warehouse via T-SQL, but a lakehouse requires a python notebook? Journey with me to the heart of data warehousing in Fabric, parquet files and the Polaris engine. We'll trace how a T-SQL query becomes distributed Parquet reads, how transactions work over immutable files, and why V-Order matters more than you think. We'll connect the theory to real-world pain with some common problems and how to resolve them like the trickle-insert trap, the delete spiral, and the .orderBy() trap. Come curious, leave dangerous.

This is a 400 level session. We'll be diving into the polaris white paper concepts to understand how the Fabric Warehouse is able to live on parquet but be fed by T-SQL.