JSON_PUBLISH is a table operator that is used to compose a JSON data type instance or instances from a variety of data sources, basically anything that can be referenced in an SQL statement. It can publish data into any supported JSON format, including the binary storage formats. JSON_PUBLISH also has the ability to aggregate data larger than 64K into a JSON document.
JSON_PUBLISH returns one output column called data, which is the resulting JSON document. The return type of this table operator is always a maximum size JSON data type.
JSON_PUBLISH can compose data into a JSON data type of any character set or storage format using the RETURNS clause of the table operators. The default is to return maximum size JSON CHARACTER SET LATIN instances.