flink-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (FLINK-4691) Add group-windows for streaming tables
Date Wed, 05 Oct 2016 15:17:20 GMT

    [ https://issues.apache.org/jira/browse/FLINK-4691?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15549043#comment-15549043
] 

ASF GitHub Bot commented on FLINK-4691:
---------------------------------------

Github user twalthr commented on a diff in the pull request:

    https://github.com/apache/flink/pull/2562#discussion_r81997213
  
    --- Diff: flink-libraries/flink-table/src/main/scala/org/apache/flink/api/table/windows.scala
---
    @@ -0,0 +1,340 @@
    +/*
    + * 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.api.table
    +
    +import org.apache.flink.api.table.expressions.{Expression, ExpressionParser}
    +import org.apache.flink.api.table.plan.logical._
    +
    +/**
    +  * Group-window specification. Group-windows allow aggregates which are computed for
a group of
    +  * elements. A (time or row-count) window is required to bound the infinite input stream
into a
    +  * finite group. Group-windows are evaluated once per group.
    +  */
    +trait GroupWindow {
    +
    +  /**
    +    * Converts an API class to a logical window for planning. This is an internal method.
    +    */
    +  private[flink] def toLogicalWindow: LogicalWindow
    +}
    +
    +/**
    +  * A group-window operating on event-time.
    +  *
    +  * @param timeField defines the time mode for streaming tables and acts as a time attribute
for
    +  *                  batch tables over which the query is evaluated.
    +  */
    +abstract class EventTimeWindow(timeField: Expression) extends GroupWindow {
    +
    +  protected var name: Option[Expression] = None
    +
    +  /**
    +    * Assigns an alias for this window that the following `select()` clause can refer
to in order
    +    * to access window properties such as window start or end time.
    +    *
    +    * @param alias alias for this window
    +    * @return this window
    +    */
    +  def as(alias: Expression): EventTimeWindow = {
    +    this.name = Some(alias)
    +    this
    +  }
    +
    +  /**
    +    * Assigns an alias for this window that the following `select()` clause can refer
to in order
    +    * to access window properties such as window start or end time.
    +    *
    +    * @param alias alias for this window
    +    * @return this window
    +    */
    +  def as(alias: String): EventTimeWindow = as(ExpressionParser.parseExpression(alias))
    +}
    +
    +// ------------------------------------------------------------------------------------------------
    +// Tumbling group-windows
    +// ------------------------------------------------------------------------------------------------
    +
    +/**
    +  * Tumbling group-window. By default, it works on processing-time.
    --- End diff --
    
    Done.


> Add group-windows for streaming tables	
> ---------------------------------------
>
>                 Key: FLINK-4691
>                 URL: https://issues.apache.org/jira/browse/FLINK-4691
>             Project: Flink
>          Issue Type: Sub-task
>          Components: Table API & SQL
>            Reporter: Timo Walther
>            Assignee: Timo Walther
>
> Add Tumble, Slide, Session group-windows for streaming tables as described in [FLIP-11|https://cwiki.apache.org/confluence/display/FLINK/FLIP-11%3A+Table+API+Stream+Aggregations].

> Implementation of group-windows on streaming tables. This includes implementing the API
of group-windows, the logical validation for group-windows, and the definition of the “rowtime”
and “systemtime” keywords. Group-windows on batch tables won’t be initially supported
and will throw an exception.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message