Hi Dongwon,
Couldn't you just return a tuple from the aggregation function and extract
the fields from the nested tuple using a value access function [1]?
table table2 = table1
.window(Slide.over("3.rows").every("1.rows").on("time").as("w"))
.groupBy("w, name")
.select("name, myudaf(col1, col2, col3) as x")
.select("name, x.get(0) as col4, x.get(1) as col5")
Best, Fabian
[1]
https://ci.apache.org/projects/flink/flink-docs-release-1.7/dev/table/functions.html#value-access-functions
Am Mi., 20. März 2019 um 07:15 Uhr schrieb Dongwon Kim <
[email protected]>:
> Another, yet related question:
>
> Is there something like aggregate table function?
> In the above scenario, I have to apply an aggregate function and then
> apply a table function solely to flatten tuples, which seems quite
> inefficient.
>
>
>
> On Wed, Mar 20, 2019 at 1:09 PM Dongwon Kim <[email protected]> wrote:
>
>> Hi Kurt,
>> You're right; It is table function like "mytablefunc(col1, col2, col3) as
>> (col4, col5)".
>> I've got to define a custom UDTF for that purpose.
>> Thanks,
>>
>> - Dongwon
>>
>> On Wed, Mar 20, 2019 at 12:04 PM Kurt Young <[email protected]> wrote:
>>
>>> Hi Dongwon,
>>>
>>> AFAIK, Flink doesn't support the usage like "myscalar(col1, col2, col3)
>>> as (col4, col5)". Am I missing something?
>>>
>>> If you want to split Tuple2 into two different columns, you can use
>>> UDTF.
>>>
>>> Best,
>>> Kurt
>>>
>>>
>>> On Wed, Mar 20, 2019 at 9:59 AM Dongwon Kim <[email protected]>
>>> wrote:
>>>
>>>> Hi,
>>>>
>>>> I want to split Tuple2 returned by AggregateFunction.getValue into two
>>>> different columns in a resultant table.
>>>>
>>>> Let's consider the following example where myudaf returns
>>>> Tuple2<Boolean, Boolean>:
>>>>
>>>> Table table2 = table1
>>>> .window(Slide.over("3.rows").every("1.rows").on("time").as("w"))
>>>> .groupBy("w, name")
>>>> .select("name, myudaf(col1, col2, col3) as (col4, col5)")
>>>>
>>>> Then table2.printSchema() returns (w/ Flink 1.7.2)
>>>>
>>>> root
>>>> |-- name: String
>>>> |-- col4: Java Tuple2<Boolean, Boolean>
>>>>
>>>> whereas my expectation is
>>>>
>>>> root
>>>> |-- name: String
>>>> |-- col4: Boolean
>>>> |-- col5: Boolean
>>>>
>>>> When I define a scalar function which returns Tuple2 and use like
>>>> "myscalar(col1, col2, col3) as (col4, col5)", it works as expected.
>>>>
>>>> Is there a possible way of splitting the tuple into two different
>>>> columns in Flink-1.7.2?
>>>> If not, do I have to define an additional UDF in order to flatten the
>>>> tuple? or there's already one I can make use of?
>>>>
>>>> - Dongwon
>>>
>>>
