Synopsis: 

DATABASE()

Input: none

Output: string

Description: Returns the name of the database being queried. In the case of Elasticsearch SQL, this is the name of the Elasticsearch cluster. This function should always return a non-null value.

SELECT DATABASE();

   DATABASE
---------------
elasticsearch

Synopsis: 

USER()

Input: none

Output: string

Description: Returns the username of the authenticated user executing the query. This function can return null in case Security is disabled.

SELECT USER();

     USER
---------------
elastic