@Entity
@Table(name = "MESSAGE_HISTORY_RECORD")

public class MessageHistoryRecord {

    @EmbeddedId
    private MessageCompoundKey compoundKey;

    @Column
    private String responseChannel;

    @ElementCollection
    private List<Trace> traces;

    @Column
    private byte[] payload;

    //getters and setters
}

@Embeddable
public class MessageCompoundKey implements Serializable {

    private static final long serialVersionUID = 9084329307727034214L;

    @Column
    private String correlatedMsgId;

    @Column
    private String messageId;

    @Column
    private String endpointId;

    //getters and setters
}

@Embeddable
public class Trace implements Serializable{

    private static final long serialVersionUID = 9084329307727034214L;

    private Long timestamp;

    private String description;

   //getters and setters
}

CREATE TABLE "public"."message_history_record"
(
   correlatedmsgid varchar(255) NOT NULL,
   endpointid varchar(255) NOT NULL,
   messageid varchar(255) NOT NULL,
   payload bytea,
   responsechannel varchar(255),
   CONSTRAINT message_history_record_pkey PRIMARY KEY (correlatedmsgid,endpointid,messageid)
)
;
CREATE UNIQUE INDEX message_history_record_pkey ON "public"."message_history_record"
(
  correlatedmsgid,
  endpointid,
  messageid
)
;

CREATE TABLE "public"."messagehistoryrecord_traces"
(
   messagehistoryrecord_correlatedmsgid varchar(255) NOT NULL,
   messagehistoryrecord_endpointid varchar(255) NOT NULL,
   messagehistoryrecord_messageid varchar(255) NOT NULL,
   description varchar(255),
   timestamp bigint
)

hibernate.connection.driver_class=org.postgresql.Driver
hibernate.connection.url=jdbc:postgresql://192.xx.xx.xx:5432/testdb
hibernate.connection.username=***
hibernate.connection.password=****
hibernate.dialect=org.hibernate.dialect.PostgreSQLDialect
hibernate.connection.pool_size=10
hibernate.show_sql=true
hibernate.hbm2ddl.auto=update

@ElementCollection
@CollectionTable(name = "mhr_traces",
    joinColumns={@JoinColumn(name="mhr_correlatedmsgid", referencedColumnName="correlatedmsgid"),
                 @JoinColumn(name="mhr_endpointid", referencedColumnName="endpointid"),
                 @JoinColumn(name = "mhr_messageid", referencedColumnName = "messageid")})
private List<Trace> traces = new ArrayList<>();

CONSTRAINT mrFK FOREIGN KEY (mhr_correlatedmsgid, mhr_endpointid, mhr_messageid) REFERENCES MESSAGE_HISTORY_RECORD (correlatedmsgid,endpointid,messageid)