     name TEXT NOT NULL, -- name of the client
     created_on DATETIME NOT NULL,
     modified_on TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
-)
+) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

    modified_on TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
    UNIQUE KEY (eid),
    KEY(eid, session_id, user_id)
)

-- client stores data about clients that use our API
CREATE TABLE client (

    user_id CHAR(64) CHARACTER SET latin1 NOT NULL,
    body TEXT NOT NULL,
    KEY (eid, session_id, user_id)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;

-- session survey responses.
CREATE TABLE session_survey_responses (
