[
https://issues.apache.org/jira/browse/FLINK-5767?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15878159#comment-15878159
]
ASF GitHub Bot commented on FLINK-5767:
---------------------------------------
Github user fhueske commented on a diff in the pull request:
https://github.com/apache/flink/pull/3354#discussion_r102265663
--- Diff:
flink-libraries/flink-table/src/main/scala/org/apache/flink/table/functions/builtInAggFuncs/SumAggFunction.scala
---
@@ -0,0 +1,146 @@
+/*
+ * 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.flink.table.functions.builtInAggFuncs
+
+import java.math.BigDecimal
+import org.apache.flink.table.functions.{Accumulator, AggregateFunction}
+
+/**
+ * Base class for built-in Sum aggregate function
+ *
+ * @tparam T the type for the aggregation result
+ */
+abstract class SumAggFunction[T: Numeric] extends AggregateFunction[T] {
+ /** The initial accumulator for Sum aggregate function */
+ class SumAccumulator[T] extends Accumulator {
+ var sum: Option[T] = None
--- End diff --
why working with `Option` here? The other functions where initialized with
`null`. We should keep that consistent, IMO.
> New aggregate function interface and built-in aggregate functions
> -----------------------------------------------------------------
>
> Key: FLINK-5767
> URL: https://issues.apache.org/jira/browse/FLINK-5767
> Project: Flink
> Issue Type: Sub-task
> Components: Table API & SQL
> Reporter: Shaoxuan Wang
> Assignee: Shaoxuan Wang
>
> Add a new aggregate function interface. This includes implementing the
> aggregate interface, migrating the existing aggregation functions to this
> interface, and adding the unit tests for these functions.
--
This message was sent by Atlassian JIRA
(v6.3.15#6346)
