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From Philip Lee <philjj...@gmail.com>
Subject Re: Hi, question about orderBy two columns more
Date Mon, 02 Nov 2015 11:58:35 GMT
Thanks for your reply, Stephan.

So you said this is same as SQL
but I got this result from this code. This is what we did not expect, right?

val inputTuple = Seq((2,5),(2,3),(2,4),(3,2),(3,6))

val outputTuple = env.fromCollection(inputTuple)
  .sortPartition(0,Order.DESCENDING)
  //.sortPartition(1,Order.ASCENDING)
  .print()

Output:
(3,2)
(3,6)
(2,5)
(2,3)
(2,4)

val inputTuple = Seq((2,5),(2,3),(2,4),(3,2),(3,6))

val outputTuple = env.fromCollection(inputTuple)
  .sortPartition(0,Order.DESCENDING)
  .sortPartition(1,Order.ASCENDING)
  .print()

**
Actual Output:
(3,2)
(2,3)
(2,4)
(2,5)
(3,6)
‚Äč
*Expected Output:*
*(3,2)*
*(3,6)*
*(2,3)*
*(2,4)*
*(2,5)*


Thanks,
Phil


On Mon, Nov 2, 2015 at 5:54 AM, Stephan Ewen <sewen@apache.org> wrote:

> Actually, sortPartition(col1).sortPartition(col2) results in a single sort
> that primarily sorts after col1 and secondarily sorts after col2, so it is
> the same as in SQL when you state "ORDER BY col1, col2".
>
> The SortPartitionOperator created with the first "sortPartition(col1)"
> call appends further columns, rather than instantiating a new sort.
>
> Greetings,
> Stephan
>
>
> On Sun, Nov 1, 2015 at 11:29 AM, Philip Lee <philjjoon@gmail.com> wrote:
>
>> Hi,
>>
>> I know when applying order by col, it would be
>> sortPartition(col).setParralism(1)
>>
>> What about orderBy two columns more?
>> If the sql is to state order by col_1, col_2,  sortPartition().
>> sortPartition () does not solve this SQL.
>>
>> because orderby in sql is to sort the fisrt coulmn and the second column
>> in the sorted first column. but for flink the funtion totally sorts each
>> column.
>>
>> Any suggestion?
>>
>> Thanks,
>> phil
>>
>>
>

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