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ValueAggregatorDescriptor (Apache Hadoop Main 0.23.1 API)
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org.apache.hadoop.mapred.lib.aggregate</FONT>
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Interface ValueAggregatorDescriptor</H2>
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<DT><B>All Superinterfaces:</B> <DD><A HREF="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html" title="interface in org.apache.hadoop.mapreduce.lib.aggregate">ValueAggregatorDescriptor</A></DD>
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<DT><PRE><FONT SIZE="-1">@InterfaceAudience.Public
@InterfaceStability.Stable
</FONT>public interface <A HREF="../../../../../../src-html/org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html#line.39"><B>ValueAggregatorDescriptor</B></A><DT>extends <A HREF="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html" title="interface in org.apache.hadoop.mapreduce.lib.aggregate">ValueAggregatorDescriptor</A></DL>
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<P>
This interface defines the contract a value aggregator descriptor must
 support. Such a descriptor can be configured with a JobConf object. Its main
 function is to generate a list of aggregation-id/value pairs. An aggregation
 id encodes an aggregation type which is used to guide the way to aggregate
 the value in the reduce/combiner phrase of an Aggregate based job.The mapper in
 an Aggregate based map/reduce job may create one or more of
 ValueAggregatorDescriptor objects at configuration time. For each input
 key/value pair, the mapper will use those objects to create aggregation
 id/value pairs.
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<CODE>static&nbsp;<A HREF="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</A></CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html#ONE">ONE</A></B></CODE>

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<CODE>static&nbsp;<A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A></CODE></FONT></TD>
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<CODE>&nbsp;void</CODE></FONT></TD>
<TD><CODE><B><A HREF="../../../../../../org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html#configure(org.apache.hadoop.mapred.JobConf)">configure</A></B>(<A HREF="../../../../../../org/apache/hadoop/mapred/JobConf.html" title="class in org.apache.hadoop.mapred">JobConf</A>&nbsp;job)</CODE>

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&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Configure the object</TD>
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<TH ALIGN="left"><B>Methods inherited from interface org.apache.hadoop.mapreduce.lib.aggregate.<A HREF="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html" title="interface in org.apache.hadoop.mapreduce.lib.aggregate">ValueAggregatorDescriptor</A></B></TH>
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<TD><CODE><A HREF="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html#configure(org.apache.hadoop.conf.Configuration)">configure</A>, <A HREF="../../../../../../org/apache/hadoop/mapreduce/lib/aggregate/ValueAggregatorDescriptor.html#generateKeyValPairs(java.lang.Object, java.lang.Object)">generateKeyValPairs</A></CODE></TD>
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static final <A HREF="http://download.oracle.com/javase/6/docs/api/java/lang/String.html?is-external=true" title="class or interface in java.lang">String</A> <A HREF="../../../../../../src-html/org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html#line.42"><B>TYPE_SEPARATOR</B></A></PRE>
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<DT><B>See Also:</B><DD><A HREF="../../../../../../constant-values.html#org.apache.hadoop.mapred.lib.aggregate.ValueAggregatorDescriptor.TYPE_SEPARATOR">Constant Field Values</A></DL>
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ONE</H3>
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static final <A HREF="../../../../../../org/apache/hadoop/io/Text.html" title="class in org.apache.hadoop.io">Text</A> <A HREF="../../../../../../src-html/org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html#line.45"><B>ONE</B></A></PRE>
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<A NAME="configure(org.apache.hadoop.mapred.JobConf)"><!-- --></A><H3>
configure</H3>
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void <A HREF="../../../../../../src-html/org/apache/hadoop/mapred/lib/aggregate/ValueAggregatorDescriptor.html#line.55"><B>configure</B></A>(<A HREF="../../../../../../org/apache/hadoop/mapred/JobConf.html" title="class in org.apache.hadoop.mapred">JobConf</A>&nbsp;job)</PRE>
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<DD>Configure the object
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<DT><B>Parameters:</B><DD><CODE>job</CODE> - a JobConf object that may contain the information that can be used
          to configure the object.</DL>
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