@Test
  public void testInsertFromJoiningTwoIcebergTables() throws IOException {
    PartitionSpec spec = PartitionSpec.builderFor(HiveIcebergStorageHandlerTestUtils.CUSTOMER_SCHEMA)
        .identity("last_name").build();
    testTables.createTable(shell, "source_customers_1", HiveIcebergStorageHandlerTestUtils.CUSTOMER_SCHEMA,
        spec, fileFormat, HiveIcebergStorageHandlerTestUtils.CUSTOMER_RECORDS);
    testTables.createTable(shell, "source_customers_2", HiveIcebergStorageHandlerTestUtils.CUSTOMER_SCHEMA,
        spec, fileFormat, HiveIcebergStorageHandlerTestUtils.CUSTOMER_RECORDS);
    Table table = testTables.createTable(shell, "target_customers",
        HiveIcebergStorageHandlerTestUtils.CUSTOMER_SCHEMA, spec, fileFormat, ImmutableList.of());

    shell.executeStatement("INSERT INTO target_customers SELECT a.customer_id, b.first_name, a.last_name FROM " +
        "source_customers_1 a JOIN source_customers_2 b ON a.last_name = b.last_name");

    HiveIcebergTestUtils.validateData(table, HiveIcebergStorageHandlerTestUtils.CUSTOMER_RECORDS, 0);
  }
Testing map-reduce inserts.
@throws IOException If there is an underlying IOException
iceberg/iceberg-handler/src/test/java/org/apache/iceberg/mr/hive/TestHiveIcebergInserts.java