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| <h2 title="Uses of Class org.apache.hadoop.mapreduce.Reducer" class="title">Uses of Class<br>org.apache.hadoop.mapreduce.Reducer</h2> |
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| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing packages, and an explanation"> |
| <caption><span>Packages that use <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Package</th> |
| <th class="colLast" scope="col">Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="#org.apache.hadoop.mapreduce">org.apache.hadoop.mapreduce</a></td> |
| <td class="colLast"> </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><a href="#org.apache.hadoop.mapreduce.lib.aggregate">org.apache.hadoop.mapreduce.lib.aggregate</a></td> |
| <td class="colLast"> </td> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="#org.apache.hadoop.mapreduce.lib.chain">org.apache.hadoop.mapreduce.lib.chain</a></td> |
| <td class="colLast"> </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><a href="#org.apache.hadoop.mapreduce.lib.fieldsel">org.apache.hadoop.mapreduce.lib.fieldsel</a></td> |
| <td class="colLast"> </td> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><a href="#org.apache.hadoop.mapreduce.lib.reduce">org.apache.hadoop.mapreduce.lib.reduce</a></td> |
| <td class="colLast"> </td> |
| </tr> |
| </tbody> |
| </table> |
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| <li class="blockList"> |
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| </a> |
| <h3>Uses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/package-summary.html">org.apache.hadoop.mapreduce</a></h3> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing methods, and an explanation"> |
| <caption><span>Methods in <a href="../../../../../org/apache/hadoop/mapreduce/package-summary.html">org.apache.hadoop.mapreduce</a> that return types with arguments of type <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Method and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><? extends <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a><?,?,?,?>></code></td> |
| <td class="colLast"><span class="typeNameLabel">JobContext.</span><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/JobContext.html#getCombinerClass--">getCombinerClass</a></span>()</code> |
| <div class="block">Get the combiner class for the job.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><code><a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><? extends <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a><?,?,?,?>></code></td> |
| <td class="colLast"><span class="typeNameLabel">JobContext.</span><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/JobContext.html#getReducerClass--">getReducerClass</a></span>()</code> |
| <div class="block">Get the <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce"><code>Reducer</code></a> class for the job.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing methods, and an explanation"> |
| <caption><span>Method parameters in <a href="../../../../../org/apache/hadoop/mapreduce/package-summary.html">org.apache.hadoop.mapreduce</a> with type arguments of type <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Method and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code>void</code></td> |
| <td class="colLast"><span class="typeNameLabel">Job.</span><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/Job.html#setCombinerClass-java.lang.Class-">setCombinerClass</a></span>(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><? extends <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a>> cls)</code> |
| <div class="block">Set the combiner class for the job.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><code>void</code></td> |
| <td class="colLast"><span class="typeNameLabel">Job.</span><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/Job.html#setReducerClass-java.lang.Class-">setReducerClass</a></span>(<a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><? extends <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a>> cls)</code> |
| <div class="block">Set the <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce"><code>Reducer</code></a> for the job.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </li> |
| <li class="blockList"><a name="org.apache.hadoop.mapreduce.lib.aggregate"> |
| <!-- --> |
| </a> |
| <h3>Uses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/aggregate/package-summary.html">org.apache.hadoop.mapreduce.lib.aggregate</a></h3> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing subclasses, and an explanation"> |
| <caption><span>Subclasses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/aggregate/package-summary.html">org.apache.hadoop.mapreduce.lib.aggregate</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Class and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorCombiner.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate">ValueAggregatorCombiner</a><K1 extends <a href="../../../../../org/apache/hadoop/io/WritableComparable.html" title="interface in org.apache.hadoop.io">WritableComparable</a><?>,V1 extends <a href="../../../../../org/apache/hadoop/io/Writable.html" title="interface in org.apache.hadoop.io">Writable</a>></span></code> |
| <div class="block">This class implements the generic combiner of Aggregate.</div> |
| </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorReducer.html" title="class in org.apache.hadoop.mapreduce.lib.aggregate">ValueAggregatorReducer</a><K1 extends <a href="../../../../../org/apache/hadoop/io/WritableComparable.html" title="interface in org.apache.hadoop.io">WritableComparable</a><?>,V1 extends <a href="../../../../../org/apache/hadoop/io/Writable.html" title="interface in org.apache.hadoop.io">Writable</a>></span></code> |
| <div class="block">This class implements the generic reducer of Aggregate.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| </li> |
| <li class="blockList"><a name="org.apache.hadoop.mapreduce.lib.chain"> |
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| </a> |
| <h3>Uses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/chain/package-summary.html">org.apache.hadoop.mapreduce.lib.chain</a></h3> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing subclasses, and an explanation"> |
| <caption><span>Subclasses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/chain/package-summary.html">org.apache.hadoop.mapreduce.lib.chain</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Class and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/chain/ChainReducer.html" title="class in org.apache.hadoop.mapreduce.lib.chain">ChainReducer</a><KEYIN,VALUEIN,KEYOUT,VALUEOUT></span></code> |
| <div class="block">The ChainReducer class allows to chain multiple Mapper classes after a |
| Reducer within the Reducer task.</div> |
| </td> |
| </tr> |
| </tbody> |
| </table> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing methods, and an explanation"> |
| <caption><span>Method parameters in <a href="../../../../../org/apache/hadoop/mapreduce/lib/chain/package-summary.html">org.apache.hadoop.mapreduce.lib.chain</a> with type arguments of type <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Method and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code>static void</code></td> |
| <td class="colLast"><span class="typeNameLabel">ChainReducer.</span><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/chain/ChainReducer.html#setReducer-org.apache.hadoop.mapreduce.Job-java.lang.Class-java.lang.Class-java.lang.Class-java.lang.Class-java.lang.Class-org.apache.hadoop.conf.Configuration-">setReducer</a></span>(<a href="../../../../../org/apache/hadoop/mapreduce/Job.html" title="class in org.apache.hadoop.mapreduce">Job</a> job, |
| <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><? extends <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a>> klass, |
| <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><?> inputKeyClass, |
| <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><?> inputValueClass, |
| <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><?> outputKeyClass, |
| <a href="https://docs.oracle.com/javase/8/docs/api/java/lang/Class.html?is-external=true" title="class or interface in java.lang">Class</a><?> outputValueClass, |
| <a href="../../../../../org/apache/hadoop/conf/Configuration.html" title="class in org.apache.hadoop.conf">Configuration</a> reducerConf)</code> |
| <div class="block">Sets the <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce"><code>Reducer</code></a> class to the chain job.</div> |
| </td> |
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| <h3>Uses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/package-summary.html">org.apache.hadoop.mapreduce.lib.fieldsel</a></h3> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing subclasses, and an explanation"> |
| <caption><span>Subclasses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/package-summary.html">org.apache.hadoop.mapreduce.lib.fieldsel</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Class and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/fieldsel/FieldSelectionReducer.html" title="class in org.apache.hadoop.mapreduce.lib.fieldsel">FieldSelectionReducer</a><K,V></span></code> |
| <div class="block">This class implements a reducer class that can be used to perform field |
| selections in a manner similar to unix cut.</div> |
| </td> |
| </tr> |
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| </li> |
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| <h3>Uses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/reduce/package-summary.html">org.apache.hadoop.mapreduce.lib.reduce</a></h3> |
| <table class="useSummary" border="0" cellpadding="3" cellspacing="0" summary="Use table, listing subclasses, and an explanation"> |
| <caption><span>Subclasses of <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce">Reducer</a> in <a href="../../../../../org/apache/hadoop/mapreduce/lib/reduce/package-summary.html">org.apache.hadoop.mapreduce.lib.reduce</a></span><span class="tabEnd"> </span></caption> |
| <tr> |
| <th class="colFirst" scope="col">Modifier and Type</th> |
| <th class="colLast" scope="col">Class and Description</th> |
| </tr> |
| <tbody> |
| <tr class="altColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/reduce/IntSumReducer.html" title="class in org.apache.hadoop.mapreduce.lib.reduce">IntSumReducer</a><Key></span></code> </td> |
| </tr> |
| <tr class="rowColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/reduce/LongSumReducer.html" title="class in org.apache.hadoop.mapreduce.lib.reduce">LongSumReducer</a><KEY></span></code> </td> |
| </tr> |
| <tr class="altColor"> |
| <td class="colFirst"><code>class </code></td> |
| <td class="colLast"><code><span class="memberNameLink"><a href="../../../../../org/apache/hadoop/mapreduce/lib/reduce/WrappedReducer.html" title="class in org.apache.hadoop.mapreduce.lib.reduce">WrappedReducer</a><KEYIN,VALUEIN,KEYOUT,VALUEOUT></span></code> |
| <div class="block">A <a href="../../../../../org/apache/hadoop/mapreduce/Reducer.html" title="class in org.apache.hadoop.mapreduce"><code>Reducer</code></a> which wraps a given one to allow for custom |
| <code>Reducer.Context</code> implementations.</div> |
| </td> |
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