PolyBase

PolyBase is a SQL Server feature that allows you to run T-SQL queries over external data sources like Hadoop, Azure Blob Storage, and even other relational databases. First introduced in SQL Server 2016, it bridges the gap between relational and big data ecosystems.

With PolyBase, DBAs can:

• Query CSV, ORC, or Parquet files in external storage.
• Connect to remote SQL, Oracle, or Teradata systems.
• Use T-SQL syntax without ETL jobs.

It works via external tables and data sources and integrates with Synapse and Azure Data Lake. PolyBase is ideal for hybrid data architectures, allowing SQL Server to function as a central access point for disparate sources.