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From Jacques Nadeau <jacq...@apache.org>
Subject Re: Min max aggregated function
Date Mon, 03 Jun 2013 16:43:05 GMT
See below

On Fri, May 31, 2013 at 8:47 AM, Alexandre BECHE
<alexandre.beche@gmail.com> wrote:
> Thanks all for your comments,
>
> Now I would like to understand few things:
> If I well understood, the files I created (MinAggregator.java and
> MaxAggregator.java under
> incubator-drill/sandbox/prototype/exec/ref/src/main/java/org/apache/drill/exec/ref/eval/fn)
> are part of the Logical plan, is that correct?

Yes, that makes sense

>
> Then, when I execute the example through the maven command : mvn exec:java
> -Dexec.mainClass="org.apache.drill.exec.ref.ReferenceInterpreter"
> -Dexec.classpathScope=test -Dexec.args="src/test/resources/simple_scan.json"
> The query goes to the physical plan (Which tell me how to interact with
> json, could be anything else) and is executing on my datasource: json in
> that case (the logical plan is datasource-agnostic)?

The path is the logical plan.  Currently, the reference interpreter
only has a driver to access json.  The full execution engine will have
many more.

>
> Finally, when trying to write this two functions, I found another potential
> place in the sources to put them:
> plan-parser/src/main/java/org/apache/drill/plan/json/ScalarAggregate.java
> However, it was not necessary to modify it for the example to behave as
> expected.
> What is exactly this function, why I didn't had to modify it to get the
> example working?

That location is for queries written in SQL.  Your submitting a
logical plan which is a lower level concept and bypasses the SQL
parser.

Thanks for your contribution, I'm hoping someone will do a first pass
review soon.

thanks,
Jacques

>
> Thanks in advance for your help,
> Cheers,
> Alex
>
>
>
> On Thu, May 30, 2013 at 10:05 PM, Ted Dunning <ted.dunning@gmail.com> wrote:
>
>> The author is the drill project.  This mailing list is the place to go for
>> questions.
>>
>> The person who typed the semi-colons is probably here, bit so are the
>> people who designed the API and who worked through the architecture.  By
>> asking everybody you get access to answers you may not have known you
>> needed.
>>
>> Besides that makes it easy for you to remember.
>>
>> Sent from my iPhone
>>
>> On May 30, 2013, at 15:51, Alexandre BECHE <alexandre.beche@gmail.com>
>> wrote:
>>
>> > Do you know who is the original author of the Count and Sum function? I
>> > would like to discuss with him on ir if possible.
>>

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