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Pig, mail # user - wrong sort order (lexical vs numeric) in a nested foreach


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Re: wrong sort order (lexical vs numeric) in a nested foreach
Dmitriy Ryaboy 2012-09-01, 04:42
I tried to reproduce this and haven't been able to -- all my devious
attempts to get something that is actually a string to show up as an
int in "describe" wind up in class cast exceptions and blown up jobs
(not devious enough, clearly).

Can you give put together an example that reproduces the issue, and
let us know which version of pig you are running?

Thanks,
Dmitriy

On Fri, Aug 31, 2012 at 2:42 AM, Lauren Blau
<[EMAIL PROTECTED]> wrote:
> Could this be a problem with the original read of the data. It is stored in
> Json format and read with a custom Json loader.
> If I save the results of the loader to a file using PigStorage and then run
> the same script reading from that file the sort is done numerically.
>
> I've had other pig script problems which have been solved by explicitly
> storing and re-reading using PigStorage.
> I'm not sure what I can check in the loader (I didn't write it) to see what
> might be causing this,
> Any hints on how to debug this?
>
> Thanks,
> Lauren
>
> On Thu, Aug 30, 2012 at 6:10 PM, Lauren Blau <
> [EMAIL PROTECTED]> wrote:
>
>> sorry, premature email :-).
>>
>> relation = key1 ,key2,orderkey1,val; //schema is
>> (chararray,int,int,chararray);
>>
>> groupbykey = group relation by (key1,key2);
>> foreach groupbykey {
>>     sorted = order  relation by orderkey1;
>>     generate flatten($0), MyUDF(sorted);
>> }
>>
>> I notice that when the 'sorted' values arrive in my UDF, they are sorted
>> lexically, not numerically. I checked the schema on the way in and
>> orderkey1 is definitely an int.
>>
>> Is there any way to force the order by into a numeric sort?
>>
>> Thanks,
>> Lauren
>>
>>
>> On Thu, Aug 30, 2012 at 5:59 PM, Lauren Blau <
>> [EMAIL PROTECTED]> wrote:
>>
>>> I have the following foreach:
>>>
>>> foo := foreach bar {
>>>
>>>
>>