This document provides an overview of SQL Server 2019 Big Data Clusters, which enable hybrid SQL Server/Spark scale-out data platforms that run on Kubernetes. Big Data Clusters are available in public preview and will generally be available in the second half of 2019. They provide a true scale-out data platform for aggregating data from various sources, using data science tools with sensitive data on the same platform, and storing/querying large amounts of unstructured data with SQL Server tools.