MySQL 5.7 Release Notes
X Plugin extends MySQL Server to be able to function as a document store. Running X Plugin enables MySQL Server to communicate with clients using the X Protocol, which is designed to expose the ACID compliant storage abilities of MySQL as a document store. Documents are stored in JSON format and enable schema-less storage. Using the X DevAPI you can use a NoSQL-like syntax to execute Create, Read, Update, Delete (CRUD) operations against these documents.
This section explains how to install, configure, and monitor X Plugin in MySQL Server.