wypoon commented on a change in pull request #4395: URL: https://github.com/apache/iceberg/pull/4395#discussion_r835721927
########## File path: spark/v3.2/spark/src/main/java/org/apache/iceberg/spark/source/NumFiles.java ########## @@ -0,0 +1,45 @@ +/* + * 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. + */ + +package org.apache.iceberg.spark.source; + +import java.text.NumberFormat; +import org.apache.spark.sql.connector.metric.CustomMetric; + +public class NumFiles implements CustomMetric { + + @Override + public String name() { + return "numFiles"; + } + + @Override + public String description() { + return "number of files read"; + } + + @Override + public String aggregateTaskMetrics(long[] taskMetrics) { + long sum = initialValue; + for (int i = 0; i < taskMetrics.length; i++) { + sum += taskMetrics[i]; + } + return NumberFormat.getIntegerInstance().format(sum); + } Review comment: @RussellSpitzer I think you may be thinking of task metrics that Spark itself collects (by default, Duration, GC Time, Input Size / Records, and Shuffle Size /Records are shown), and are shown with the min, 25th percentile, median, 75th percentile, and max. For custom `SQLMetric`s, one implements the `aggregateTaskMetrics` and we'd need to do the calculation ourselves if we want such statistics. Spark doesn't do it for us. Spark sends all the values it collected from all the `PartitionReader`s for a given custom metric in a `long[]` to this `aggregateTaskMetrics`; that's all. It also doesn't separately calculate these statistics either. -- 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. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
