CREATE TABLE COMMENT_HISTORY (
    ID NUMBER(19) PRIMARY KEY,
    REFERENCE_ID VARCHAR2(100) NOT NULL,
    REFERENCE_TYPE VARCHAR2(100) NOT NULL,
    COMMENT_TYPE VARCHAR2(100) NOT NULL,
    COMMENT_TEXT CLOB
);

CREATE SEQUENCE comment_history_seq
  START WITH 1
  INCREMENT BY 1
  NOMINVALUE
  NOMAXVALUE
  NOCACHE
  NOCYCLE;