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From Matthew Hayes <matthew.terence.ha...@gmail.com>
Subject Re: why is data.fu implementing HyperLogLog as an accumulator and not as algebraic?
Date Sun, 17 May 2015 17:37:22 GMT
Hey sorry for the delay.  I took a look at the diff and replied with some
comments in the JIRA.  Please take a look, thanks.

-Matt

On Sat, May 9, 2015 at 10:53 PM, Ido Hadanny <ido.hadanny@gmail.com> wrote:

> Hey, I see that this is still in open and un-assigned - can you assign it
> to me so I can mark it as "patch available"? or do you want me just to mark
> it as "fixed"?
>
> On 28 April 2015 at 08:37, Ido Hadanny <ido.hadanny@gmail.com> wrote:
>
>> https://issues.apache.org/jira/browse/DATAFU-91
>>
>>
>> On 27 April 2015 at 18:02, Matthew Hayes <matthew.terence.hayes@gmail.com
>> > wrote:
>>
>>> Great thanks :) Please file a JIRA and attach the patch there.
>>>
>>> -Matt
>>>
>>> On Apr 27, 2015, at 6:26 AM, Ido Hadanny <ido.hadanny@gmail.com> wrote:
>>>
>>> Hey guys,
>>> patch is attached + tested on unit-tests + We're testing it on a
>>> 1000-nodes real hadoop cluster as we speak.
>>> Do you want us to create a jira issue for this, or is this good enough?
>>> Thanks, Ilia and Ido
>>>
>>> On 7 March 2015 at 23:09, Matthew Hayes <matthew.terence.hayes@gmail.com
>>> > wrote:
>>>
>>>> I don't remember if there was a particular reason I didn't implement
>>>> this as AlgebraicEvalFunc. It seems like it could be. I believe the Java
>>>> MapReduce version leverages the combiner. If you want to try making this
>>>> Algebraic we would be happy to accept a patch :)
>>>>
>>>> -Matt
>>>>
>>>> > On Mar 7, 2015, at 12:11 PM, Ido Hadanny <ido.hadanny@gmail.com>
>>>> wrote:
>>>> >
>>>> > data.fu has a nice implementation of HyperLogLog for estimating
>>>> cardinality
>>>> > here
>>>> > <
>>>> https://github.com/apache/incubator-datafu/blob/master/datafu-pig/src/main/java/datafu/pig/stats/HyperLogLogPlusPlus.java
>>>> >
>>>> >
>>>> > However, it's implemented as Accumulator which means it will run only
>>>> at
>>>> > the reducer and not in the combiner (but it will never load the
>>>> entire set
>>>> > into memory as in normal EvalFunc). Why couldn't data.fu implement it
>>>> as
>>>> > Algebraic - and fill the registers at every combiner, then merge and
>>>> reduce
>>>> > the result? Am I missing something here?
>>>> > also available here:
>>>> >
>>>> http://stackoverflow.com/questions/28908217/why-is-data-fu-implementing-hyperloglog-as-an-accumulator-and-not-as-algebraic
>>>> >
>>>> > thanks!
>>>> >
>>>> >
>>>> > --
>>>> > Sent from my androido
>>>>
>>>
>>>
>>>
>>> --
>>> Sent from my androido
>>>
>>> <hyper-log-log-algebraic.diff>
>>>
>>>
>>
>>
>> --
>> Sent from my androido
>>
>
>
>
> --
> Sent from my androido
>

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