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From Apache Wiki <wikidi...@apache.org>
Subject [Hadoop Wiki] Update of "Hive/GenericUDAFCaseStudy" by JohnSichi
Date Fri, 28 Jan 2011 22:48:33 GMT
Dear Wiki user,

You have subscribed to a wiki page or wiki category on "Hadoop Wiki" for change notification.

The "Hive/GenericUDAFCaseStudy" page has been changed by JohnSichi.
http://wiki.apache.org/hadoop/Hive/GenericUDAFCaseStudy?action=diff&rev1=6&rev2=7

--------------------------------------------------

  || init || Called by Hive to initialize an instance of your UDAF evaluator class. ||
  || getNewAggregationBuffer || Return an object that will be used to store temporary aggregation
results. ||
  || iterate || Process a new row of data into the aggregation buffer ||
- || terminatePartial || Return the contents of the current aggregation in a serializable
way ||
+ || terminatePartial || Return the contents of the current aggregation in a persistable way.
 Here persistable means the return value can only be built up in terms of Java primitives,
arrays, primitive wrappers (e.g. Double), Hadoop Writables, Lists, and Maps.  Do NOT use your
own classes (even if they implement java.io.Serializable), otherwise you may get strange errors
or (probably worse) wrong results.  ||
  || merge || Merge a partial aggregation returned by '''terminatePartial''' into the current
aggregation ||
  || terminate || Return the final result of the aggregation to Hive ||
  

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