[ 
https://issues.apache.org/jira/browse/FLINK-3849?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15928394#comment-15928394
 ] 

ASF GitHub Bot commented on FLINK-3849:
---------------------------------------

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

    https://github.com/apache/flink/pull/3520#discussion_r106468487
  
    --- Diff: 
flink-libraries/flink-table/src/test/scala/org/apache/flink/table/utils/TestFilterableTableSource.scala
 ---
    @@ -0,0 +1,142 @@
    +/*
    + * 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.utils
    +
    +import org.apache.flink.api.common.typeinfo.TypeInformation
    +import org.apache.flink.api.java.typeutils.RowTypeInfo
    +import org.apache.flink.api.java.{DataSet, ExecutionEnvironment}
    +import org.apache.flink.streaming.api.datastream.DataStream
    +import 
org.apache.flink.streaming.api.environment.StreamExecutionEnvironment
    +import org.apache.flink.table.api.Types._
    +import org.apache.flink.table.expressions._
    +import org.apache.flink.table.sources.{BatchTableSource, 
FilterableTableSource, StreamTableSource, TableSource}
    +import org.apache.flink.types.Row
    +import org.apache.flink.util.Preconditions
    +
    +import scala.collection.JavaConverters._
    +import scala.collection.mutable
    +import scala.tools.nsc.interpreter.JList
    +
    +/**
    +  * This source can only handle simple comparision with field "amount".
    +  * Supports ">, <, >=, <=, =, <>" with an integer.
    +  */
    +class TestFilterableTableSource(
    +    val recordNum: Int = 33)
    +    extends BatchTableSource[Row]
    +        with StreamTableSource[Row]
    +        with FilterableTableSource[Row] {
    +
    +  var filterPushedDown: Boolean = false
    +
    +  val fieldNames: Array[String] = Array("name", "id", "amount", "price")
    +
    +  val fieldTypes: Array[TypeInformation[_]] = Array(STRING, LONG, INT, 
DOUBLE)
    +
    +  // all predicates with filed "amount"
    +  private var filterPredicates = new mutable.ArrayBuffer[Expression]
    +
    +  // all comparing values for field "amount"
    +  private val filterValues = new mutable.ArrayBuffer[Int]
    +
    +  override def getDataSet(execEnv: ExecutionEnvironment): DataSet[Row] = {
    +    execEnv.fromCollection[Row](generateDynamicCollection().asJava, 
getReturnType)
    +  }
    +
    +  override def getDataStream(execEnv: StreamExecutionEnvironment): 
DataStream[Row] = {
    +    execEnv.fromCollection[Row](generateDynamicCollection().asJava, 
getReturnType)
    +  }
    +
    +  override def explainSource(): String = {
    +    if (filterPredicates.nonEmpty) {
    +      s"filter=[${filterPredicates.reduce((l, r) => And(l, r)).toString}]"
    +    } else {
    +      ""
    +    }
    +  }
    +
    +  override def getReturnType: TypeInformation[Row] = new 
RowTypeInfo(fieldTypes, fieldNames)
    +
    +  override def applyPredicate(predicates: JList[Expression]): 
TableSource[Row] = {
    +    val newSource = new TestFilterableTableSource(recordNum)
    +    newSource.filterPushedDown = true
    +
    +    val iterator = predicates.iterator()
    +    while (iterator.hasNext) {
    +      iterator.next() match {
    +        case expr: BinaryComparison =>
    +          (expr.left, expr.right) match {
    +            case (f: ResolvedFieldReference, v: Literal) if 
f.name.equals("amount") =>
    +              newSource.filterPredicates += expr
    +              newSource.filterValues += 
v.value.asInstanceOf[Number].intValue()
    +              iterator.remove()
    +            case (_, _) =>
    +          }
    +      }
    +    }
    +
    +    newSource
    +  }
    +
    +  override def isFilterPushedDown: Boolean = filterPushedDown
    +
    +  private def generateDynamicCollection(): Seq[Row] = {
    +    Preconditions.checkArgument(filterPredicates.length == 
filterValues.length)
    +
    +    for {
    +      cnt <- 0 until recordNum
    +      if shouldCreateRow(cnt)
    +    } yield {
    +      val row = new Row(fieldNames.length)
    --- End diff --
    
    can be simplified to 
    ```
    val row = Row.of(
            s"Record_$cnt",
            cnt.toLong.asInstanceOf[Object],
            cnt.toInt.asInstanceOf[Object],
            cnt.toDouble.asInstanceOf[Object])
    ```


> Add FilterableTableSource interface and translation rule
> --------------------------------------------------------
>
>                 Key: FLINK-3849
>                 URL: https://issues.apache.org/jira/browse/FLINK-3849
>             Project: Flink
>          Issue Type: New Feature
>          Components: Table API & SQL
>            Reporter: Fabian Hueske
>            Assignee: Kurt Young
>
> Add a {{FilterableTableSource}} interface for {{TableSource}} implementations 
> which support filter push-down.
> The interface could look as follows
> {code}
> def trait FilterableTableSource {
>   // returns unsupported predicate expression
>   def setPredicate(predicate: Expression): Expression
> }
> {code}
> In addition we need Calcite rules to push a predicate (or parts of it) into a 
> TableScan that refers to a {{FilterableTableSource}}. We might need to tweak 
> the cost model as well to push the optimizer in the right direction.



--
This message was sent by Atlassian JIRA
(v6.3.15#6346)

Reply via email to