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Hive >> mail # user >> UDAF terminatePartial structure


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Ritesh Agrawal 2013-07-29, 22:19
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Robin Morris 2013-07-29, 23:15
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Ritesh Agrawal 2013-07-29, 23:32
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Re: UDAF terminatePartial structure
I found this Cloudera example helpful:
http://grepcode.com/file/repository.cloudera.com/content/repositories/releases/org.apache.hadoop.hive/hive-contrib/0.7.0-cdh3u0/org/apache/hadoop/hive/contrib/udaf/example/UDAFExampleMaxMinNUtil.java#UDAFExampleMaxMinNUtil.Evaluator

igor
decide.com

On Mon, Jul 29, 2013 at 4:32 PM, Ritesh Agrawal <[EMAIL PROTECTED]>wrote:

> Hi Robin,
>
> Thanks for the suggestion. I did find such an example in Hadoop The
> definitive guide book. However I am not total confused.
>
> The book extends UDAF instead of AbstractGenericUDAFResolver. Which one is
> recommended ?
>
> Also the example in the book uses DoubleWritable as a return type for the
> "terminate" function. However, I will be returning an arraylist of double.
> Do I always need to written objects that are derived from
> WritableComponents.
>
> Ritesh
> On Jul 29, 2013, at 4:15 PM, Robin Morris wrote:
>
> > I believe a map will be passed correctly from the terminatePartial to the
> > merge functions.  But it seems a bit of overkill.
> >
> > Why not define a class within your UDAF which has 4 public data members,
> > and return instances of that class from terminatePartial()?
> >
> > Robin
> >
> >
> > On 7/29/13 3:19 PM, "Ritesh Agrawal" <[EMAIL PROTECTED]> wrote:
> >
> >> Hi all,
> >>
> >> I am writing my first UDAF. In my terminatePartial() function, I need to
> >> store different data having different data types. Below is a list of
> >> items that I need to store
> >> 1. C1 : list of doubles
> >> 2. C2: list of doubles
> >> 3. C3: double
> >> 4. Show: list of strings
> >>
> >>
> >> I am wondering can I use simple HashMap and store these different
> objects
> >> into it. Will it automatically serialize or will I need to write my own
> >> serializiable method. Also is there any example of a UDAF that shows how
> >> to use map type structure for storing partial results.
> >>
> >> Thanks
> >>
> >> Ritesh
> >
>
>
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Ritesh Agrawal 2013-07-30, 04:12
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Robin Morris 2013-07-30, 06:04