I linked some time ago to a post
that talked about the next generation of exciting OLAP data stores—Clickhouse, Druid, and Pinot—and I continue to follow this space with interest. This release from the Pinot team @ Linkedin caught my eye for this specific improvement:
We moved from custom PQL to Calcite SQL. Apache Calcite is a popular open source framework for building databases and data management systems. It includes a SQL parser, an API for building expressions in relational algebra, and a query-planning engine. We have leveraged the Calcite SQL parser to parse queries in SQL format. However, Pinot continues to support only a subset of SQL; for instance, joins and nested queries are not supported. This is a design choice in Pinot to focus on providing fast analytics on a single table.
This is a big deal! SQL support allows Pinot to enter the analytics ecosystem in a first-class way.