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Posted to dev@kafka.apache.org by Boyang Chen <bc...@outlook.com> on 2018/11/01 17:38:10 UTC
KSQL with changelog topic
Hey there,
a dumb question that I haven't found the answer anywhere: does KSQL support query towards Stream applications'
changelog topic? Especially window store changelog, since it has a more complex key schema.
Thanks!
Re: KSQL with changelog topic
Posted by Boyang Chen <bc...@outlook.com>.
Thanks for confirming!
________________________________
From: Matthias J. Sax <ma...@confluent.io>
Sent: Saturday, November 3, 2018 1:35 AM
To: dev@kafka.apache.org
Subject: Re: KSQL with changelog topic
I see. Makes sense.
AFAIK, this is not supported atm, because KSQL cannot handle the
`Windowed<K>` datatype yet.
-Matthias
On 11/1/18 9:28 PM, Boyang Chen wrote:
> For example, I have a stream windowed aggregation changlog topic KStream--XXX--changelog-000026, does KSQL support a simple query like
>
> ```
>
> select * from
>
> changelog_topic
>
> limit 10
>
> ```
>
> I'm not sure because the serde for window store changelog is compound Windowed<K>.
>
>
> Hope this makes sense. Thank you!
>
>
> ________________________________
> From: Matthias J. Sax <ma...@confluent.io>
> Sent: Friday, November 2, 2018 5:06 AM
> To: dev@kafka.apache.org
> Subject: Re: KSQL with changelog topic
>
> I am not sure if I understand the question. Can you elaborate?
>
> -Matthias
>
>
> On 11/1/18 10:38 AM, Boyang Chen wrote:
>> Hey there,
>>
>>
>> a dumb question that I haven't found the answer anywhere: does KSQL support query towards Stream applications'
>>
>> changelog topic? Especially window store changelog, since it has a more complex key schema.
>>
>>
>> Thanks!
>>
>
>
Re: KSQL with changelog topic
Posted by "Matthias J. Sax" <ma...@confluent.io>.
I see. Makes sense.
AFAIK, this is not supported atm, because KSQL cannot handle the
`Windowed<K>` datatype yet.
-Matthias
On 11/1/18 9:28 PM, Boyang Chen wrote:
> For example, I have a stream windowed aggregation changlog topic KStream--XXX--changelog-000026, does KSQL support a simple query like
>
> ```
>
> select * from
>
> changelog_topic
>
> limit 10
>
> ```
>
> I'm not sure because the serde for window store changelog is compound Windowed<K>.
>
>
> Hope this makes sense. Thank you!
>
>
> ________________________________
> From: Matthias J. Sax <ma...@confluent.io>
> Sent: Friday, November 2, 2018 5:06 AM
> To: dev@kafka.apache.org
> Subject: Re: KSQL with changelog topic
>
> I am not sure if I understand the question. Can you elaborate?
>
> -Matthias
>
>
> On 11/1/18 10:38 AM, Boyang Chen wrote:
>> Hey there,
>>
>>
>> a dumb question that I haven't found the answer anywhere: does KSQL support query towards Stream applications'
>>
>> changelog topic? Especially window store changelog, since it has a more complex key schema.
>>
>>
>> Thanks!
>>
>
>
Re: KSQL with changelog topic
Posted by Boyang Chen <bc...@outlook.com>.
For example, I have a stream windowed aggregation changlog topic KStream--XXX--changelog-000026, does KSQL support a simple query like
```
select * from
changelog_topic
limit 10
```
I'm not sure because the serde for window store changelog is compound Windowed<K>.
Hope this makes sense. Thank you!
________________________________
From: Matthias J. Sax <ma...@confluent.io>
Sent: Friday, November 2, 2018 5:06 AM
To: dev@kafka.apache.org
Subject: Re: KSQL with changelog topic
I am not sure if I understand the question. Can you elaborate?
-Matthias
On 11/1/18 10:38 AM, Boyang Chen wrote:
> Hey there,
>
>
> a dumb question that I haven't found the answer anywhere: does KSQL support query towards Stream applications'
>
> changelog topic? Especially window store changelog, since it has a more complex key schema.
>
>
> Thanks!
>
Re: KSQL with changelog topic
Posted by "Matthias J. Sax" <ma...@confluent.io>.
I am not sure if I understand the question. Can you elaborate?
-Matthias
On 11/1/18 10:38 AM, Boyang Chen wrote:
> Hey there,
>
>
> a dumb question that I haven't found the answer anywhere: does KSQL support query towards Stream applications'
>
> changelog topic? Especially window store changelog, since it has a more complex key schema.
>
>
> Thanks!
>