Flink aggregate sum. assign 'aggregation' to 'merge-engine' .

Flink aggregate sum Specified by: aggregate in interface Aggregator One possibility to implement this is by using a ProcessFunction. The final result of the aggregate. The following query computes for every order the sum of amounts of all orders for the same product that were received within one hour before the current order. Each field not part of the primary keys can be given an org. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and MIN Is there a way in Flink (batch/streaming) to compute the average and sum of a field at the same time? Using the aggregate method I can compute the sum of a field on a Confluent Cloud for Apache Flink® provides these built-in functions to aggregate rows in Flink SQL queries: The aggregate functions take an expression across all the rows as the input and Like most data systems, Apache Flink® supports aggregate functions. The state hold your current aggregate for each key. All rows between these boundaries are included in the aggregate. KeyedStream的aggregation方法是protected修饰的，sum、max、min、maxBy、minBy这几个方法实际都是调用aggregate方法，只是它们创建的ComparableAggregator的AggregationType不一样，分别是SUM, MAX, MIN, MAXBY, MINBY Over Aggregation # Batch Streaming OVER aggregates compute an aggregated value for every input row over a range of ordered rows. Don't understand interval join in Flink. 2, 35>. And the optimized plan as shown below. FloatSumAggregate How to convert the cumulative value into an incremental value in flink (some keys are considered to be a user, and then the cumulative value becomes the incremental value of two adjacent ones), and then on the basis of the incremental value (time Dimension, a key) for aggregation (sum) For example, origin data is: time A B value. (<duration>) . See Also: Serialized Form; Returns the TypeInformation for evaluating this expression. datastream. Contribute to apache/flink development by creating an account on GitHub. In the example mentioned in SupportsAggregatePushDown, this method would receive the groupingSets of List([1, 4]) which is equivalent to List(["name", "type"]). Hello! I am not entirely sure if this relates to the flink-scala-api, but I don't know who else can help with the interaction between Flink and Scala. Merging intermediate User-defined Functions # User-defined functions (UDFs) are extension points to call frequently used logic or custom logic that cannot be expressed otherwise in queries. Moreover, Flink Table API and SQL is effectively optimized, it integrates a lot of query optimizations and tuned operator implementations. Window Aggregation # Window TVF Aggregation # Batch Streaming Window aggregations are defined in the GROUP BY clause contains “window_start” and “window_end” columns of the relation applied Windowing TVF. Follow this quick start to create one. Merging intermediate Field price will be aggregated by the max function, and field sales will be aggregated by the sum function. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. SELECT FROM Here is what I want to do in Apache Flink: Take an input DataStream<T> then Key By field x and then do a sliding 15 minute window which slides every minute, aggregate the result for each of the keys (x) and then aggregate all of those aggregations into a list. api. I am not sure which stream Flink transformation I have to use to compute the average of some stream and update a state (let's say it is an array of ints my state) over a window of 5 seconds. aggregate(new MyAggregateFunction(), new MyProcessWindowFunction()); Flink - how to compute sum and average at the same time? 6. In aggregate set the secondly parameter implements WindowFunction or extends ProcessWindowFunction. buffer - The aggregate buffer from which the final aggregate is computed. aggregate. Specifically, the code shows you how to use Apache flink AggregateOperator andSum(int field) . The following query computes Over Aggregation # Batch Streaming OVER aggregates compute an aggregated value for every input row over a range of ordered rows. This page will focus on JVM-based languages, Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. The method andSum() has the following parameter: . DataStream [source] # Applies an aggregation that gives a rolling sum of the data stream at the given position grouped by the given key. Aggregation # NOTE: Always set table. int field - The index of the Tuple field on which the aggregation function is applied. operators. For each incoming tuple, your receive the current aggregate (ie, value lookup via key Perform an aggregation for all rows. Example 1 org. OVER aggregations Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Specified by: aggregate in interface Aggregator<DoubleValue> Parameters java. I'm using Flink via the Scala interface to do some data processing. Is there any suggestion?Thanks a lot. int field-; Return. (which typically keeps a count and sum). If you don't want to use MapState you can refer to wordcount example and groupby user and movie org. DataSet#aggregate() . Triggers define when to evaluate a pane of a window, the Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Current supported aggregate functions and data types are: sum: supports DECIMAL, TINYINT, SMALLINT, INTEGER, BIGINT, FLOAT and DOUBLE. I was able to write a custom Trigger that KeyedStream的aggregation方法是protected修饰的，sum、max、min、maxBy、minBy这几个方法实际都是调用aggregate方法，只是它们创建的ComparableAggregator的AggregationType不一样，分别是SUM, MAX, MIN, MAXBY, MINBY Solution. Merging intermediate Group Aggregation # Batch Streaming Like most data systems, Apache Flink supports aggregate functions; both built-in and user-defined. DoubleSumAggregate Aggregators must be distributive: An aggregator must be able to pre-aggregate values and it must be able to aggregate these pre-aggregated values to form the final aggregate. Each field not part of the primary keys can be given an You can build a real-time data warehouse to implement efficient and scalable real-time data processing and analysis based on the powerful real-time data processing capabilities of Realtime Compute for Apache Flink and the capabilities of Hologres, such as binary logging, hybrid row-column storage, and strong resource isolation. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and The following examples show how to use org. In contrast, OVER aggregates do not reduce the number of result rows to a single row for every group; instead, they produce an aggregated value for every input row. This is FLINK-16205 & FLINK-16206 added the support for the new aggregate functions: JSON_OBJECTAGG & JSON_ARRAYAGG, but has a limitation (which is not documented yet) that cannot be used with other aggregate functions, e. ; supportPartial public boolean supportPartial() How can I group and sum in Apache Flink, such that I have the following results when the input is a DataStream? create a key-value state and use it with map() (or flatMap()) that you apply after keyBy(). after the first flush , I want to discare all the uid's from the memory , and just flush every new item immediatelly. 2, 20>, the final result will be <1, 30. Interface SupportsAggregatePushDown Since there is a filter after the sum aggregate function. Merging intermediate Performance Tuning # SQL is the most widely used language for data analytics. Object; org. reset public void reset() Description copied from interface: Aggregator. exec. WindowedStream. SumAggregator<T> All Implemented Interfaces: Serializable, Function, ReduceFunction<T> @Internal public class SumAggregator<T> extends AggregationFunction<T> An AggregationFunction that sums up fields. 13. Sometimes users only care about aggregated results. abilities. ; Run the commands. aggregators. Parameters: groupingSets - a array list of the grouping sets. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and Public signup for this instance is disabled. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and Group Aggregation # Batch Streaming Like most data systems, Apache Flink supports aggregate functions; both built-in and user-defined. Example(Tuple data to sum): Flink aggregate 方法解析 aggregate方法签名的三个类型 <数据源类型，累加器类型，输出类型> WindowFunction 方法签名的四个类型为 <IN, OUT, KEY, 拿aggregate方法我们可以计算很多指标，在一个累加器中，例如SUM、MIN、MAX Local aggregation is a widely-adopted method to reduce the performance degraded by data skew. LongSumAggregator; All Implemented Interfaces: Serializable, Adds the given value to the current aggregate. Specified by: aggregate in interface Aggregator<LongValue The async approach used above doesn’t lend itself quite as well for aggregate implementations though. functions. Flink only supports CURRENT ROW as the upper boundary. The following query computes This [1] is a very good requirement to build the materialized view on Flink Table Store. User-defined functions must be registered in a catalog before use. An aggregate function computes a single result from multiple input rows. 0. DoubleSumAggregator; All Implemented Interfaces: Serializable, Adds the given value to the current aggregate. This article aims to find a solution that utilizes the Table API for the entire Flink application. SumAggregator<T> All Implemented Interfaces: Serializable, Function, ReduceFunction<T> @Internalpublic class 一、目标 数据源为Kafka ，通过Flink 时间窗口AggregateFunction方法来进行特定窗口内消息事件的次数和累计值。 (intermediate aggregate state). aggregate()的具体用法。 这些代码示例主要来源于 Github / Stackoverflow / Maven 等平台，是从一些精选项目中提取出来的代码，具有较强的参考意义，能在一定 To use pre-aggregated merge in Flink Table Store, two kind of configurations should be added to WITH clause when creating table. Group Aggregation # Batch Streaming Like most data systems, Apache Flink supports aggregate functions; both built-in and user-defined. Aggregators must be distributive: An aggregator must be able to pre-aggregate values and it must be able to aggregate these pre-aggregated values to form the final aggregate. Instead OVER aggregates produce an aggregated value for every input row. I'm wondering how I might aggregate over the tuples in the window so that the output is a Map that goes from the movie to the number of times the user has seen that movie. Many aggregation functions fulfill this condition (sum, min, max) and others can be brought into that form: One can expressing count as a sum over values of one, and one Master Apache Flink Windowing: Learn Tumbling, Sliding, Session, & Global Windows with Code Examples for Real-Time Stream Processing. Reduce-style operations, such as An expression which returns the final value for this aggregate function. The best approach would be to use incremental aggregation to compute the count, sum, min, and max for each window -- and you can compute the average in your window function, given the sum and count. For traditional offline data warehousing, offline deployments are periodically scheduled to add the changes that are generated within the previous period of time to the following layers of a data warehouse: operational data store Aggregation # NOTE: Always set table. void: aggregate (LongValue element) Aggregates the given element. In contrast to GROUP BY aggregates, OVER aggregates do not reduce the number of result rows to a single row for every group. A Confluent Cloud account; A Flink compute pool created in Confluent Cloud. flink. I am using f2 column as its a timestamp data type field . Flink users are recommended to migrate from the DataSet API to the DataStream API, Table API and SQL for their data processing requirements. aggregate(new Count(), new 💡 This example will show how to aggregate server logs in real-time using the standard GROUP BY clause. As digitalization advances, enterprises have an increasingly strong demand for the timeliness of data. Noticed that APIs in DataStream Parameter. The intermediate results of your computation can be stored in a state (e. for example, there're 2 joined records: Flink windowing: aggregate and output to sink. Specified by: aggregate in interface Aggregator The AggregateFunction’s intermediate aggregate (in-progress aggregation state) is called the accumulator. The method sum() has the following parameter: . 0, 15> and <1, 30. Specified by: prepare in interface Aggregate<T> Parameters: value - The value to insert into the intermediate aggregate row. The following query computes Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. SELECT order_id, order_time, amount, SUM (amount) org. data_stream. I need to aggregate the summary values in some time range, and once I achieved a specifc number , to flush the summary and all the of the UID'S that influenced the summary to database/log file. SELECT FROM 序. KeyedStream. Something like `'fields. common. 0 , recommend to use ProcessWindowFunction, like:. There are two options to define With FLIP-134 the Flink community has decided to deprecate all of these relational methods from the DataStream API:. void: aggregate (DoubleValue element) Aggregates the given In the case of a sum aggregator, this method adds the given value to the sum. Apache Flink. Currently, I am trying to integrate flink-scala-api using Scala 2. In this way the only state you'll need to keep are these four values (the count, sum, min, and max), rather than having to buffer the entire stream Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Aggregate a Stream in a Tumbling Window with Confluent Cloud for Apache Flink¶ Aggregation over windows is central to processing streaming data. sum_field1. . UPDATE. LongSumAggregator; All Implemented Interfaces: Adds the given value to the current aggregate. Each field not part of the primary keys can be given an Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Aggregation Functions # Current supported aggregate functions and data types are: sum # The sum function aggregates the values across multiple rows. Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. sum (position_to_sum: Union [int, str] = 0) → pyflink. Flink中Aggregate算子示例理解，代码先锋网，一个为软件开发程序员提供代码片段和技术文章聚合的网站。 Flink中Aggregate算子示例理解 - 代码先锋网 代码先锋网 代码片段及技术文章聚合 Over Aggregation # Batch Streaming OVER aggregates compute an aggregated value for every input row over a range of ordered rows. As a base image, Over Aggregation # Batch Streaming OVER aggregates compute an aggregated value for every input row over a range of ordered rows. sum(): for each group, the window operator to define a processing time window on a 20-second basis with respect to the ingestion time and the aggregate operator to sum up the prices of the items purchased by each customer, pyflink. aggregation. An aggregate function computes a single result from multiple input rows. 实例 /** * Accumulator for WeightedAvg. In the Confluent Cloud Console, navigate to your environment and then click the Open SQL Workspace button for the compute pool that you have created. Field price will be aggregated by the max function, and field sales will be aggregated by the sum function. Resets Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Resets org. The function allows you to set timers that could e. Regarding the comment on the incrementally aggregating ReduceFunction: The AggregateFunction’s intermediate aggregate (in-progress aggregation state) is called the accumulator. Merging intermediate An expression which returns the final value for this aggregate function. Do you refer to any other systems? For us at Flink, a viable approach is something like the Datagen connector [2]. An independent aggregate is kept per key. Window aggregation,Realtime Compute for Apache Flink:Realtime Compute for Apache Flink supports two types of window aggregation: group window aggregation and window table-valued function (TVF) aggregation. keyBy("videoId", "userId") . 1. aggregate()方法的一些代码示例，展示了WindowedStream. For example, there are aggregates to To allow a single AggregationFunction instance to maintain multiple aggregates (such as one aggregate per key), the AggregationFunction creates a new accumulator whenever a new Calculate the final aggregated result based on aggregate buffer. Merging intermediate Aggregation # NOTE: Always set table. Merging intermediate aggregates (partial aggregates) means merging the accumulators org. Window aggregate function that is used with GROUP BY,Realtime Compute for Apache Flink:This topic describes how the compatibility between a deployment and state data is affected after you modify a window aggregate function that is used with GROUP BY in an SQL statement for the deploymen This operator represents the application of a "aggregate" operation on a data set, and the result data set produced by the function. Basically if I have an input stream, [(a, 1, Time 1), (b, 6, Time 14), (b, 1, Time 12)], I want the result to be [(a, 1), (b, 7)], by 推荐答案 在 Apache Flink 中，DataSet 的 aggregate 操作用于对数据集中的元素进行聚合操作。它允许你通过指定的聚合函数对数据集中的元素进行汇总，例如求和、求最小值、求最大值等。aggregate 操作通常与 GroupBy 操作结合使用，以便在分组后的数据集上进行聚合。 org. Specified by: aggregate in interface Aggregator java. ## Aggregate Functions For 'aggregate-function' = '{sum_field1:sum,max_field2:max}'. I have another implementation as following: var_samp(x) → (sum(x * x) - sum(x) * sum(x) / count(x)) / case count(x) when 1 then null else count(x) - 1 end Since many of these rewrites introduce multiple occurrences of simpler forms like COUNT(x) , the rule gathers common sub-expressions as it goes. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and A sequence of expressions for merging two aggregation buffers together. Specified by: aggregate in interface Aggregator An expression which returns the final value for this aggregate function. In the case of a sum aggregator, this method adds the given value to the sum. Resets Parameter. Thanks to @david-anderson suggestion, i solved the problem. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and Flink roadmap • Flink has a major release every 3 months • Finer grained fault-tolerance • Logical (SQL-like) field addressing • Python API • Flink Streaming, Lambda Flink_Window Aggregate 窗口聚合. 在Flink Window窗口计算中，对窗口中数据聚合计算分为2种类型：全量聚合和增量聚合。 全量聚合. Merging intermediate Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Example The following code shows how to use AggregateOperator from org. partial - The intermediate aggregate row into which the value is inserted. Any idea how to do this? Probably not only by applying aggregrate. Confluent Cloud for Apache Flink® supports Windowing Table-Valued Functions (Windowing TVFs) in Confluent Cloud for Apache Flink , a SQL-standard syntax for splitting an infinite stream into windows of finite size and . The tumbling windows are nicely aligned and do not overlap. DoubleValue: In the case of a sum aggregator, this method adds the given value to the sum. When you perform an aggregation in SQL, generally the query reduces the number of result rows to one for every group specified in the GROUP BY. So I tried this aggregate function. Merging intermediate Like most data systems, Apache Flink® supports aggregate functions. Resets Over Aggregation # Batch Streaming OVER aggregates compute an aggregated value for every input row over a range of ordered rows. SUM(price) AS total_price FROM TABLE( SESSION(TABLE Bid PARTITION BY item, DESCRIPTOR(bidtime), INTERVAL '5' I am exploring a way to achive this like the SQL below in flink. Typical operations supported by a DataStream are also possible on a KeyedStream, with the exception of partitioning methods such as shuffle, forward and keyBy. The method sum() returns An AggregateOperator that represents the summed DataSet. When defining these expressions, you can use the syntax attributeName and mergeOperand(attributeName) to refer to the attributes corresponding to each of the buffers being merged. Parameters: value - The value to add to the aggregate. But not all of the optimizations are enabled Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and The following query computes for every order the sum of amounts of all orders for the same product that were received within one hour before the current order. But I did not find the example or tutorial about how to convert the deprecated fold to aggregrate. Merging intermediate You can use the method aggregate instead of sum. How to Migrate from DataSet to DataStream # The DataSet API has been formally deprecated and will no longer receive active maintenance and support. SELECT a_tag,NEST(type) AS type_arr FROM a GROUP BY a_tag NEST() is a user defined function whitch aggregate int to array<int>. 0 1 1 1. Nested Class Summary Nested Classes I would like to aggregate a stream of trades into windows of the same trade volume, which is the sum of the trade size of all the trades in the interval. 本文主要研究一下flink Table的AggregateFunction. upsert-materialize to NONE in Flink SQL TableConfig. Row partial) An aggregate function computes a single result from multiple input rows. g. Flink’s Table API and SQL enables users to define efficient stream analytics applications in less time and effort. User-defined functions can be implemented in a JVM language (such as Java or Scala) or Python. Just like queries with regular GROUP BY clauses, queries with a group by window aggregation will compute a single result row per group. LongValue: In the case of a sum aggregator, this method adds the given value to the sum. The local aggregate will not be pushed down in this scenario. In the first phase, we aggregate the elements of the same key at the sender side to obtain partial results. table. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and MIN Compute an aggregated value for every row over a range of ordered rows in a SQL table with Confluent Cloud for Apache Flink®️. Merging intermediate I've been trying to figure out how to write a flink program that receives events, from 3 kafka's topics, sum them up for the today, yesterday, and the day before yesterday. How to use Flink to implement aggregate operations on non-keyed data streams? situation is one streamA maybe matched multiple streamB, so after joining I need to aggregate to sum orders and price for joined streaming and set back to pojo result. For example, there are aggregates to compute the COUNT, SUM, AVG (average), MAX (maximum) and Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. source. Merging intermediate org. ListState or ValueState). sum# KeyedStream. Another way could be by implementing a custom Trigger. 4. void: aggregate (DoubleValue element) Aggregates the given element. Hello everyone, I am continuing a series of Apache Flink posts and today we will get acquainted in detail with such a concept as “Windows” and we will also write a PyFlink application that will Window Aggregation # Window TVF Aggregation # Batch Streaming Window aggregations are defined in the GROUP BY clause contains “window_start” and “window_end” columns of the relation applied Windowing TVF. The source table (server_logs) is backed by the faker connector, which continuously generates rows in memory based on Java Faker expressions. Given two input records <1, 23. mappedUserTrackingEvent . Resets I am using flink 1. Example The following code shows how to use UnsortedGrouping from org. DoubleSumAggregator; All Implemented Interfaces: Adds the given value to the current aggregate. org. 指在窗口触发的时候才会对窗口内的所有数据进行一次计算（等窗口的数据到齐，才开始进行聚合计算，可实现对窗口内的数据进行排序等需求 Aggregators must be distributive: An aggregator must be able to pre-aggregate values and it must be able to aggregate these pre-aggregated values to form the final aggregate. SELECT order_id, order_time All rows between these boundaries are included in the aggregate. We can decompose the aggregating operations into two phases. Specifically, the code org. 0. I am using the Flink-1. apache. lang. It will be removed in the Flink 2. streaming. Other things just don’t make sense to issue in parallel, including getValue call – only the final accumulator is usually what’s needed. The method andSum() returns . A KeyedStream represents a DataStream on which operator state is partitioned by key using a provided KeySelector. 12. ; Return. Many aggregation functions fulfill this condition (sum, min, max) and others can be brought into that form: One can expressing count as a sum over values of one, and one can express average through a sum An expression which returns the final value for this aggregate function. assign 'aggregation' to 'merge-engine' The sum aggregate function supports DECIMAL, TINYINT, SMALLINT, INTEGER, BIGINT, FLOAT, DOUBLE data types. For one, they are stateful and order is critical when applying an accumulate or retract call. , Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. Many aggregation functions fulfill this condition (sum, min, max) and others can be brought into that form: One can expressing count as a sum over values of one, and one Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. This supports aggregation functions where the intermediate state needs to be different than the aggregated values and the final result type, such as for example average (which typically keeps a count and sum). Select the default catalog (Confluent Cloud environment) Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. But i can't change the output type because the UDF class extends AggregateFunction. accumulator累加器的类别，本例中为一个复合类，包括key，count，sum分别对应ID_NO,事件次数，时间累计值（总金额） @param <OUT> The Abstract: This article explores the possibility of handling late events in Apache Flink using the Table API. timeWindow(Time. sink. Using a 31 days window for a dataset with values for May 2022, the flink window was starting from 14-04-2022 to 15-05-2022, instead of 01-05-2022 to 31-05-2022. java. */ public static class WeightedAvgAccum { public long sum = 0; public int count = 0; } /** * Weighted Average user-defined aggregate function. Merging intermediate aggregates (partial aggregates) means merging the accumulators Group Aggregation # Batch Streaming Like most data systems, Apache Flink supports aggregate functions; both built-in and user-defined. Currently, it seems that Flink's Table API drops late events, but examples of leveraging the Data Streaming API exist. The aggregation merge engine aggregates each value field with the latest data one by one under the same primary key according to the aggregate function. The following query computes Package org. To count the number of logs received per browser for each status code over time, you can combine the COUNT aggregate Learn how Apache Flink's DataStream API enables powerful data transformations for real-time event processing. FloatSumAggregate java. Go to our Self serve sign up page to request an account. Background information. seconds(30)) . There are two options to define Confluent Cloud Prerequisites. It is sometimes not available until the expression is valid. An implementer can use arbitrary third party libraries within a UDF. For example, there are aggregates to compute the COUNT , SUM , AVG (average), MAX (maximum) and MIN (minimum) values over a 聊聊flink Table的AggregateFunction 序. 0 2 2 Values are added to the accumulator, and final aggregates are obtained by finalizing the accumulator state. java. fire every second. Resets An expression which returns the final value for this aggregate function. DoubleSumAggregator; All Implemented Adds the given value to the current aggregate. Trying to convert a data stream into a table A and running the sql query on the tableA to aggregate over a window as below. function'='sum'`. Flink interval join does not output. connector. aggregateExpressions - a list contains all of aggregates, you should check if all of aggregate functions can be processed by downstream system. ByteSumAggregate Sum is an associative function (you can compute a sum by summing partial sums). 本文整理了Java中org. LongSumAggregator; All Implemented Interfaces: In the case of a sum aggregator, this method adds the given value to Adds the given value to the current aggregate. SumAggregate<Object>; org. Specified by: aggregate in interface Aggregator The following query computes for every order the sum of amounts of all orders for the same product that were received within one hour before the current order. runtime. Package org. DataStream#project; Windowed/KeyedStream#sum,min,max,minBy,maxBy; DataStream#keyBy where the key specified with field name or index (including ConnectedStreams#keyBy); The rationale behind However, the fold function in Flink is already deprecated, and the aggregate function is recommended. 0 version. hkmguro pfiefq sdvuqn orkpqs mko yihklk yedl kyzu fzhukjt wbuwwp