@Test
  public void testLoadNamespaceMeta() throws TException {
    Namespace namespace = Namespace.of("dbname_load");

    catalog.createNamespace(namespace, meta);

    Map<String, String> nameMata = catalog.loadNamespaceMetadata(namespace);
    assertThat(nameMata).containsEntry("owner", "apache");
    assertThat(nameMata).containsEntry("group", "iceberg");
    assertThat(catalog.convertToDatabase(namespace, meta).getLocationUri())
        .as("There no same location for db and namespace")
        .isEqualTo(nameMata.get("location"));
  }
Run all the tests from abstract of {@link CatalogTests} with few specific tests related to HIVE.
iceberg/iceberg-catalog/src/test/java/org/apache/iceberg/hive/TestHiveCatalog.java