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| <div class="subTitle">org.apache.beam.sdk.transforms</div> |
| <h2 title="Class GroupByKey" class="title">Class GroupByKey<K,V></h2> |
| </div> |
| <div class="contentContainer"> |
| <ul class="inheritance"> |
| <li>java.lang.Object</li> |
| <li> |
| <ul class="inheritance"> |
| <li><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html" title="class in org.apache.beam.sdk.transforms">org.apache.beam.sdk.transforms.PTransform</a><<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>>,<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,java.lang.Iterable<V>>>></li> |
| <li> |
| <ul class="inheritance"> |
| <li>org.apache.beam.sdk.transforms.GroupByKey<K,V></li> |
| </ul> |
| </li> |
| </ul> |
| </li> |
| </ul> |
| <div class="description"> |
| <ul class="blockList"> |
| <li class="blockList"> |
| <dl> |
| <dt><span class="paramLabel">Type Parameters:</span></dt> |
| <dd><code>K</code> - the type of the keys of the input and output <code>PCollection</code>s</dd> |
| <dd><code>V</code> - the type of the values of the input <code>PCollection</code> and the elements of the <code>Iterable</code>s in the output <code>PCollection</code></dd> |
| </dl> |
| <dl> |
| <dt>All Implemented Interfaces:</dt> |
| <dd>java.io.Serializable, <a href="../../../../../org/apache/beam/sdk/transforms/display/HasDisplayData.html" title="interface in org.apache.beam.sdk.transforms.display">HasDisplayData</a></dd> |
| </dl> |
| <hr> |
| <br> |
| <pre>public class <span class="typeNameLabel">GroupByKey<K,V></span> |
| extends <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html" title="class in org.apache.beam.sdk.transforms">PTransform</a><<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>>,<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,java.lang.Iterable<V>>>></pre> |
| <div class="block"><code>GroupByKey<K, V></code> takes a <code>PCollection<KV<K, V>></code>, groups the values by key and |
| windows, and returns a <code>PCollection<KV<K, Iterable<V>>></code> representing a map from each |
| distinct key and window of the input <code>PCollection</code> to an <code>Iterable</code> over all the |
| values associated with that key in the input per window. Absent repeatedly-firing <a href="../../../../../org/apache/beam/sdk/transforms/windowing/Window.html#triggering-org.apache.beam.sdk.transforms.windowing.Trigger-"><code>triggering</code></a>, each key in the output <code>PCollection</code> is unique within each |
| window. |
| |
| <p><code>GroupByKey</code> is analogous to converting a multi-map into a uni-map, and related to |
| <code>GROUP BY</code> in SQL. It corresponds to the "shuffle" step between the Mapper and the Reducer |
| in the MapReduce framework. |
| |
| <p>Two keys of type <code>K</code> are compared for equality <b>not</b> by regular Java <code>Object.equals(java.lang.Object)</code>, but instead by first encoding each of the keys using the <code>Coder</code> of the |
| keys of the input <code>PCollection</code>, and then comparing the encoded bytes. This admits |
| efficient parallel evaluation. Note that this requires that the <code>Coder</code> of the keys be |
| deterministic (see <a href="../../../../../org/apache/beam/sdk/coders/Coder.html#verifyDeterministic--"><code>Coder.verifyDeterministic()</code></a>). If the key <code>Coder</code> is not |
| deterministic, an exception is thrown at pipeline construction time. |
| |
| <p>By default, the <code>Coder</code> of the keys of the output <code>PCollection</code> is the same as |
| that of the keys of the input, and the <code>Coder</code> of the elements of the <code>Iterable</code> |
| values of the output <code>PCollection</code> is the same as the <code>Coder</code> of the values of the |
| input. |
| |
| <p>Example of use: |
| |
| <pre><code> |
| PCollection<KV<String, Doc>> urlDocPairs = ...; |
| PCollection<KV<String, Iterable<Doc>>> urlToDocs = |
| urlDocPairs.apply(GroupByKey.<String, Doc>create()); |
| PCollection<R> results = |
| urlToDocs.apply(ParDo.of(new DoFn<KV<String, Iterable<Doc>>, R>() { |
| {@literal @}ProcessElement |
| public void processElement(ProcessContext c) { |
| String url = c.element().getKey(); |
| Iterable<Doc> docsWithThatUrl = c.element().getValue(); |
| ... process all docs having that url ... |
| }})); |
| </code></pre> |
| |
| <p><code>GroupByKey</code> is a key primitive in data-parallel processing, since it is the main way to |
| efficiently bring associated data together into one location. It is also a key determiner of the |
| performance of a data-parallel pipeline. |
| |
| <p>See <a href="../../../../../org/apache/beam/sdk/transforms/join/CoGroupByKey.html" title="class in org.apache.beam.sdk.transforms.join"><code>CoGroupByKey</code></a> for a way to group multiple input |
| PCollections by a common key at once. |
| |
| <p>See <a href="../../../../../org/apache/beam/sdk/transforms/Combine.PerKey.html" title="class in org.apache.beam.sdk.transforms"><code>Combine.PerKey</code></a> for a common pattern of <code>GroupByKey</code> followed by <a href="../../../../../org/apache/beam/sdk/transforms/Combine.GroupedValues.html" title="class in org.apache.beam.sdk.transforms"><code>Combine.GroupedValues</code></a>. |
| |
| <p>When grouping, windows that can be merged according to the <a href="../../../../../org/apache/beam/sdk/transforms/windowing/WindowFn.html" title="class in org.apache.beam.sdk.transforms.windowing"><code>WindowFn</code></a> of the input |
| <code>PCollection</code> will be merged together, and a window pane corresponding to the new, merged |
| window will be created. The items in this pane will be emitted when a trigger fires. By default |
| this will be when the input sources estimate there will be no more data for the window. See |
| <a href="../../../../../org/apache/beam/sdk/transforms/windowing/AfterWatermark.html" title="class in org.apache.beam.sdk.transforms.windowing"><code>AfterWatermark</code></a> for details on the estimation. |
| |
| <p>The timestamp for each emitted pane is determined by the <a href="../../../../../org/apache/beam/sdk/transforms/windowing/Window.html#withTimestampCombiner-org.apache.beam.sdk.transforms.windowing.TimestampCombiner-"><code>Window.withTimestampCombiner(TimestampCombiner)</code></a> windowing operation}. The output <code>PCollection</code> will have the same <a href="../../../../../org/apache/beam/sdk/transforms/windowing/WindowFn.html" title="class in org.apache.beam.sdk.transforms.windowing"><code>WindowFn</code></a> as the input. |
| |
| <p>If the input <code>PCollection</code> contains late data or the <a href="../../../../../org/apache/beam/sdk/transforms/windowing/Window.html#triggering-org.apache.beam.sdk.transforms.windowing.Trigger-"><code>requested |
| TriggerFn</code></a> can fire before the watermark, then there may be multiple elements output by a <code>GroupByKey</code> that correspond to the same key and window. |
| |
| <p>If the <a href="../../../../../org/apache/beam/sdk/transforms/windowing/WindowFn.html" title="class in org.apache.beam.sdk.transforms.windowing"><code>WindowFn</code></a> of the input requires merging, it is not valid to apply another <code>GroupByKey</code> without first applying a new <a href="../../../../../org/apache/beam/sdk/transforms/windowing/WindowFn.html" title="class in org.apache.beam.sdk.transforms.windowing"><code>WindowFn</code></a> or applying <a href="../../../../../org/apache/beam/sdk/transforms/windowing/Window.html#remerge--"><code>Window.remerge()</code></a>.</div> |
| <dl> |
| <dt><span class="seeLabel">See Also:</span></dt> |
| <dd><a href="../../../../../serialized-form.html#org.apache.beam.sdk.transforms.GroupByKey">Serialized Form</a></dd> |
| </dl> |
| </li> |
| </ul> |
| </div> |
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| <!-- --> |
| </a> |
| <h3>Fields inherited from class org.apache.beam.sdk.transforms.<a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html" title="class in org.apache.beam.sdk.transforms">PTransform</a></h3> |
| <code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#name">name</a></code></li> |
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| <h3>Method Summary</h3> |
| <table class="memberSummary" border="0" cellpadding="3" cellspacing="0" summary="Method Summary table, listing methods, and an explanation"> |
| <caption><span id="t0" class="activeTableTab"><span>All Methods</span><span class="tabEnd"> </span></span><span id="t1" class="tableTab"><span><a href="javascript:show(1);">Static Methods</a></span><span class="tabEnd"> </span></span><span id="t2" class="tableTab"><span><a href="javascript:show(2);">Instance Methods</a></span><span class="tabEnd"> </span></span><span id="t4" class="tableTab"><span><a href="javascript:show(8);">Concrete Methods</a></span><span class="tabEnd"> </span></span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Method and Description</th> |
| </tr> |
| <tr id="i0" class="altColor"> |
| <td class="colFirst"><code>static void</code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#applicableTo-org.apache.beam.sdk.values.PCollection-">applicableTo</a></span>(<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><?> input)</code> </td> |
| </tr> |
| <tr id="i1" class="rowColor"> |
| <td class="colFirst"><code>static <K,V> <a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="class in org.apache.beam.sdk.transforms">GroupByKey</a><K,V></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#create--">create</a></span>()</code> |
| <div class="block">Returns a <code>GroupByKey<K, V></code> <code>PTransform</code>.</div> |
| </td> |
| </tr> |
| <tr id="i2" class="altColor"> |
| <td class="colFirst"><code><a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,java.lang.Iterable<<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>>></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#expand-org.apache.beam.sdk.values.PCollection-">expand</a></span>(<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>> input)</code> |
| <div class="block">Override this method to specify how this <code>PTransform</code> should be expanded on the given |
| <code>InputT</code>.</div> |
| </td> |
| </tr> |
| <tr id="i3" class="rowColor"> |
| <td class="colFirst"><code>boolean</code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#fewKeys--">fewKeys</a></span>()</code> |
| <div class="block">Returns whether it groups just few keys.</div> |
| </td> |
| </tr> |
| <tr id="i4" class="altColor"> |
| <td class="colFirst"><code>static <K,V> <a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><V></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#getInputValueCoder-org.apache.beam.sdk.coders.Coder-">getInputValueCoder</a></span>(<a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>> inputCoder)</code> |
| <div class="block">Returns the <code>Coder</code> of the values of the input to this transform.</div> |
| </td> |
| </tr> |
| <tr id="i5" class="rowColor"> |
| <td class="colFirst"><code>static <K,V> <a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><K></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#getKeyCoder-org.apache.beam.sdk.coders.Coder-">getKeyCoder</a></span>(<a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>> inputCoder)</code> |
| <div class="block">Returns the <code>Coder</code> of the keys of the input to this transform, which is also used as the |
| <code>Coder</code> of the keys of the output of this transform.</div> |
| </td> |
| </tr> |
| <tr id="i6" class="altColor"> |
| <td class="colFirst"><code>static <K,V> <a href="../../../../../org/apache/beam/sdk/coders/KvCoder.html" title="class in org.apache.beam.sdk.coders">KvCoder</a><K,java.lang.Iterable<V>></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#getOutputKvCoder-org.apache.beam.sdk.coders.Coder-">getOutputKvCoder</a></span>(<a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>> inputCoder)</code> |
| <div class="block">Returns the <code>Coder</code> of the output of this transform.</div> |
| </td> |
| </tr> |
| <tr id="i7" class="rowColor"> |
| <td class="colFirst"><code>void</code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#populateDisplayData-org.apache.beam.sdk.transforms.display.DisplayData.Builder-">populateDisplayData</a></span>(<a href="../../../../../org/apache/beam/sdk/transforms/display/DisplayData.Builder.html" title="interface in org.apache.beam.sdk.transforms.display">DisplayData.Builder</a> builder)</code> |
| <div class="block">Register display data for the given transform or component.</div> |
| </td> |
| </tr> |
| <tr id="i8" class="altColor"> |
| <td class="colFirst"><code><a href="../../../../../org/apache/beam/sdk/values/WindowingStrategy.html" title="class in org.apache.beam.sdk.values">WindowingStrategy</a><?,?></code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html#updateWindowingStrategy-org.apache.beam.sdk.values.WindowingStrategy-">updateWindowingStrategy</a></span>(<a href="../../../../../org/apache/beam/sdk/values/WindowingStrategy.html" title="class in org.apache.beam.sdk.values">WindowingStrategy</a><?,?> inputStrategy)</code> </td> |
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| <h3>Methods inherited from class org.apache.beam.sdk.transforms.<a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html" title="class in org.apache.beam.sdk.transforms">PTransform</a></h3> |
| <code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#compose-org.apache.beam.sdk.transforms.SerializableFunction-">compose</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#getAdditionalInputs--">getAdditionalInputs</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#getDefaultOutputCoder--">getDefaultOutputCoder</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#getDefaultOutputCoder-InputT-">getDefaultOutputCoder</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#getDefaultOutputCoder-InputT-org.apache.beam.sdk.values.PCollection-">getDefaultOutputCoder</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#getKindString--">getKindString</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#getName--">getName</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#toString--">toString</a>, <a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#validate-org.apache.beam.sdk.options.PipelineOptions-">validate</a></code></li> |
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| <code>clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait</code></li> |
| </ul> |
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| <h4>create</h4> |
| <pre>public static <K,V> <a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="class in org.apache.beam.sdk.transforms">GroupByKey</a><K,V> create()</pre> |
| <div class="block">Returns a <code>GroupByKey<K, V></code> <code>PTransform</code>.</div> |
| <dl> |
| <dt><span class="paramLabel">Type Parameters:</span></dt> |
| <dd><code>K</code> - the type of the keys of the input and output <code>PCollection</code>s</dd> |
| <dd><code>V</code> - the type of the values of the input <code>PCollection</code> and the elements of the |
| <code>Iterable</code>s in the output <code>PCollection</code></dd> |
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| <h4>fewKeys</h4> |
| <pre>public boolean fewKeys()</pre> |
| <div class="block">Returns whether it groups just few keys.</div> |
| </li> |
| </ul> |
| <a name="applicableTo-org.apache.beam.sdk.values.PCollection-"> |
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| <h4>applicableTo</h4> |
| <pre>public static void applicableTo(<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><?> input)</pre> |
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| <a name="updateWindowingStrategy-org.apache.beam.sdk.values.WindowingStrategy-"> |
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| <h4>updateWindowingStrategy</h4> |
| <pre>public <a href="../../../../../org/apache/beam/sdk/values/WindowingStrategy.html" title="class in org.apache.beam.sdk.values">WindowingStrategy</a><?,?> updateWindowingStrategy(<a href="../../../../../org/apache/beam/sdk/values/WindowingStrategy.html" title="class in org.apache.beam.sdk.values">WindowingStrategy</a><?,?> inputStrategy)</pre> |
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| <a name="expand-org.apache.beam.sdk.values.PCollection-"> |
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| <h4>expand</h4> |
| <pre>public <a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,java.lang.Iterable<<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>>> expand(<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>> input)</pre> |
| <div class="block"><span class="descfrmTypeLabel">Description copied from class: <code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#expand-InputT-">PTransform</a></code></span></div> |
| <div class="block">Override this method to specify how this <code>PTransform</code> should be expanded on the given |
| <code>InputT</code>. |
| |
| <p>NOTE: This method should not be called directly. Instead apply the <code>PTransform</code> should |
| be applied to the <code>InputT</code> using the <code>apply</code> method. |
| |
| <p>Composite transforms, which are defined in terms of other transforms, should return the |
| output of one of the composed transforms. Non-composite transforms, which do not apply any |
| transforms internally, should return a new unbound output and register evaluators (via |
| backend-specific registration methods).</div> |
| <dl> |
| <dt><span class="overrideSpecifyLabel">Specified by:</span></dt> |
| <dd><code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#expand-InputT-">expand</a></code> in class <code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html" title="class in org.apache.beam.sdk.transforms">PTransform</a><<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>>,<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,java.lang.Iterable<<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>>>></code></dd> |
| </dl> |
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| <a name="getKeyCoder-org.apache.beam.sdk.coders.Coder-"> |
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| <h4>getKeyCoder</h4> |
| <pre>public static <K,V> <a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><K> getKeyCoder(<a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>> inputCoder)</pre> |
| <div class="block">Returns the <code>Coder</code> of the keys of the input to this transform, which is also used as the |
| <code>Coder</code> of the keys of the output of this transform.</div> |
| </li> |
| </ul> |
| <a name="getInputValueCoder-org.apache.beam.sdk.coders.Coder-"> |
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| <h4>getInputValueCoder</h4> |
| <pre>public static <K,V> <a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><V> getInputValueCoder(<a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>> inputCoder)</pre> |
| <div class="block">Returns the <code>Coder</code> of the values of the input to this transform.</div> |
| </li> |
| </ul> |
| <a name="getOutputKvCoder-org.apache.beam.sdk.coders.Coder-"> |
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| <h4>getOutputKvCoder</h4> |
| <pre>public static <K,V> <a href="../../../../../org/apache/beam/sdk/coders/KvCoder.html" title="class in org.apache.beam.sdk.coders">KvCoder</a><K,java.lang.Iterable<V>> getOutputKvCoder(<a href="../../../../../org/apache/beam/sdk/coders/Coder.html" title="class in org.apache.beam.sdk.coders">Coder</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><K,V>> inputCoder)</pre> |
| <div class="block">Returns the <code>Coder</code> of the output of this transform.</div> |
| </li> |
| </ul> |
| <a name="populateDisplayData-org.apache.beam.sdk.transforms.display.DisplayData.Builder-"> |
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| <h4>populateDisplayData</h4> |
| <pre>public void populateDisplayData(<a href="../../../../../org/apache/beam/sdk/transforms/display/DisplayData.Builder.html" title="interface in org.apache.beam.sdk.transforms.display">DisplayData.Builder</a> builder)</pre> |
| <div class="block"><span class="descfrmTypeLabel">Description copied from class: <code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#populateDisplayData-org.apache.beam.sdk.transforms.display.DisplayData.Builder-">PTransform</a></code></span></div> |
| <div class="block">Register display data for the given transform or component. |
| |
| <p><code>populateDisplayData(DisplayData.Builder)</code> is invoked by Pipeline runners to collect |
| display data via <a href="../../../../../org/apache/beam/sdk/transforms/display/DisplayData.html#from-org.apache.beam.sdk.transforms.display.HasDisplayData-"><code>DisplayData.from(HasDisplayData)</code></a>. Implementations may call <code>super.populateDisplayData(builder)</code> in order to register display data in the current namespace, |
| but should otherwise use <code>subcomponent.populateDisplayData(builder)</code> to use the namespace |
| of the subcomponent. |
| |
| <p>By default, does not register any display data. Implementors may override this method to |
| provide their own display data.</div> |
| <dl> |
| <dt><span class="overrideSpecifyLabel">Specified by:</span></dt> |
| <dd><code><a href="../../../../../org/apache/beam/sdk/transforms/display/HasDisplayData.html#populateDisplayData-org.apache.beam.sdk.transforms.display.DisplayData.Builder-">populateDisplayData</a></code> in interface <code><a href="../../../../../org/apache/beam/sdk/transforms/display/HasDisplayData.html" title="interface in org.apache.beam.sdk.transforms.display">HasDisplayData</a></code></dd> |
| <dt><span class="overrideSpecifyLabel">Overrides:</span></dt> |
| <dd><code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html#populateDisplayData-org.apache.beam.sdk.transforms.display.DisplayData.Builder-">populateDisplayData</a></code> in class <code><a href="../../../../../org/apache/beam/sdk/transforms/PTransform.html" title="class in org.apache.beam.sdk.transforms">PTransform</a><<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>>,<a href="../../../../../org/apache/beam/sdk/values/PCollection.html" title="class in org.apache.beam.sdk.values">PCollection</a><<a href="../../../../../org/apache/beam/sdk/values/KV.html" title="class in org.apache.beam.sdk.values">KV</a><<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">K</a>,java.lang.Iterable<<a href="../../../../../org/apache/beam/sdk/transforms/GroupByKey.html" title="type parameter in GroupByKey">V</a>>>>></code></dd> |
| <dt><span class="paramLabel">Parameters:</span></dt> |
| <dd><code>builder</code> - The builder to populate with display data.</dd> |
| <dt><span class="seeLabel">See Also:</span></dt> |
| <dd><a href="../../../../../org/apache/beam/sdk/transforms/display/HasDisplayData.html" title="interface in org.apache.beam.sdk.transforms.display"><code>HasDisplayData</code></a></dd> |
| </dl> |
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