text: --
  --  Service states.
  --
  CREATE TABLE servicestateevents (
    servicestateevent_id int NOT NULL,
    host_id int NOT NULL,
    service_id int NOT NULL,
    start_time int NOT NULL,
  
    ack_time int default NULL,
    end_time int default NULL,
    in_downtime char(1) NOT NULL,
    last_update tinyint NOT NULL default 0,
    state tinyint NOT NULL,
  
    PRIMARY KEY (servicestateevent_id),
    UNIQUE (host_id, service_id, start_time),
    INDEX (start_time),
    INDEX (end_time),
    FOREIGN KEY (host_id, service_id) REFERENCES services (host_id, service_id)
      ON DELETE CASCADE
  );
  CREATE SEQUENCE servicestateevents_seq
  START WITH 1
  INCREMENT BY 1;
  CREATE TRIGGER servicestateevents_trigger
  BEFORE INSERT ON servicestateevents
  FOR EACH ROW
  BEGIN
    SELECT servicestateevents_seq.nextval INTO :NEW.servicestateevent_id FROM dual;
  END;
  /
  