repo.create("default", tableName + ".SubEntity2", new DatasetDescriptor.Builder()
.schema(SubEntity2.SCHEMA$)
.build());
// create composite dataset
RandomAccessDataset<Map<String, SpecificRecord>> ds = repo.load(
"default", tableName + ".SubEntity1.SubEntity2");
// Construct entities
SubEntity1 subEntity1 = SubEntity1.newBuilder().setPart1("1").setPart2("1")
.setField1("field1_1").setField2("field1_2").build();