Batch tidak berfungsi dengan GenerationType.IDENTITY
@Id
@GeneratedValue(strategy = GenerationType.IDENTITY)
Perlu menggunakan urutan.
Contoh:
@Id
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "row_generator")
@SequenceGenerator(name = "row_generator", sequenceName = "db_generator", allocationSize = 1)
private Long id;