NoSQL databases threw out SQL for querying, while their authors focused on solving problems on scale, speed and availability. The trouble is, the need for rich query never went away. Neither did SQL; it was only resting.
Today, non-relational databases are bringing back SQL-like languages and other query mechanisms to help them integrate with existing data query layers (e.g. Hibernate) and to fit in with the overwhelming weight of database query practice of the past 40 years. In this talk I’ll cover the journey from simple key-value access, through novel ideas such as Jsoniq, to where we are now with academic papers proposing a SQL++ language and projects including Cassandra, Couchbase and Aerospike providing their own SQL-like languages.