PartiQL is a SQL-compatible query language that makes it easy and efficient to process both structured (relational) data, as well as semi-structured, schemaless, and nested data, as typically found in open data formats in the Amazon S3 data lake and document-oriented databases. PartiQL is a unifying query language, enabling single-query-language access to multiple AWS services. We discuss its core tenets and how they served AWS services and Amazon projects. Then we discuss how PartiQL can benefit your applications and tools in need of unifying query access to the data lake.