Method test_rows_materialized_counters

tests/hs2/test_fetch_first.py:143–171

Test that NumRowsFetched is updated even when a fetch request is served by the results cache, and that RowsMaterialized is only updated when rows are first created (e.g. not when they are served from the cache).

(self)

  @pytest.mark.execute_serially
  @needs_session()
  def test_rows_materialized_counters(self):
    """Test that NumRowsFetched is updated even when a fetch request is served by the
    results cache, and that RowsMaterialized is only updated when rows are first created
    (e.g. not when they are served from the cache)."""
    num_rows = 10
    statement = "SELECT * FROM functional.alltypes LIMIT {0}".format(num_rows)
    num_rows_fetched = "NumRowsFetched: {0} ({0})"
    num_rows_fetched_from_cache = "NumRowsFetchedFromCache: {0} ({0})"

    # Execute the query with the results cache enabled.
    options = {self.IMPALA_RESULT_CACHING_OPT: str(num_rows)}
    handle = self.run_query_expect_success(statement, options)

    # Fetch all rows from the query and verify they have been cached.
    self.fetch_until(handle, TCLIService.TFetchOrientation.FETCH_NEXT, num_rows)
    self.__verify_num_cached_rows(num_rows)

    # Get the runtime profile and validate that NumRowsFetched and RowsMaterialized both
    # equal the number of rows fetched by the query.
    profile = self.__get_runtime_profile(handle)
    assert num_rows_fetched.format(num_rows) in profile

    # Fetch all rows again and confirm that RowsMaterialized is unchanged, but
    # NumRowsFetched is double the number of rows returned by the query.
    self.fetch_until(handle, TCLIService.TFetchOrientation.FETCH_FIRST, num_rows)
    profile = self.__get_runtime_profile(handle)
    assert num_rows_fetched.format(num_rows) in profile
    assert num_rows_fetched_from_cache.format(num_rows) in profile
    self.close(handle)

  def __get_runtime_profile(self, op_handle):
    """Helper method to get the runtime profile from a given operation handle."""