leiyiz commented on a change in pull request #12580: URL: https://github.com/apache/beam/pull/12580#discussion_r474853944
########## File path: sdks/python/apache_beam/testing/benchmarks/nexmark/queries/query7.py ########## @@ -0,0 +1,59 @@ +# +# Licensed to the Apache Software Foundation (ASF) under one or more +# contributor license agreements. See the NOTICE file distributed with +# this work for additional information regarding copyright ownership. +# The ASF licenses this file to You under the Apache License, Version 2.0 +# (the "License"); you may not use this file except in compliance with +# the License. You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +""" +Query 7, 'Highest Bid'. Select the bids with the highest bid price in the +last minute. In CQL syntax:: + + SELECT Rstream(B.auction, B.price, B.bidder) + FROM Bid [RANGE 1 MINUTE SLIDE 1 MINUTE] B + WHERE B.price = (SELECT MAX(B1.price) + FROM BID [RANGE 1 MINUTE SLIDE 1 MINUTE] B1); + +We will use a shorter window to help make testing easier. We'll also +implement this using a side-input in order to exercise that functionality. +(A combiner, as used in Query 5, is a more efficient approach.). +""" + +from __future__ import absolute_import + +import apache_beam as beam +from apache_beam.testing.benchmarks.nexmark.queries import nexmark_query_util +from apache_beam.transforms import window + + +def load(events, metadata=None): + # window bids into fixed window + sliding_bids = ( + events + | nexmark_query_util.JustBids() + | beam.WindowInto(window.FixedWindows(metadata.get('window_size_sec')))) + # find the largest price in all bids per window + max_prices = ( + sliding_bids + | beam.Map(lambda bid: bid.price) + | beam.CombineGlobally(max).without_defaults()) + return ( + sliding_bids + | 'select_bids' >> beam.ParDo( + SelectMaxBidFn(), beam.pvalue.AsSingleton(max_prices))) Review comment: Yeah, I read the code and the reason to not use combiner, which is more efficient, is to utilize the side-input functionality ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
