# Window of message batch
**URL:** https://forum.confluent.io/t/window-of-message-batch/4821
**Category:** ksqlDB
**Created:** [20 April 2022 03:07 UTC](https://forum.confluent.io/t/window-of-message-batch/4821 "2022-04-20T03:07:10Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@shubhamshirur](https://forum.confluent.io/u/shubhamshirur)
#### Post date: [20 April 2022 03:07 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/1 "2022-04-20T03:07:10Z")
Hi there,
We can limit a stream for aggregation or stream-stream operations by window of time. Can we apply window of count of messages ?
For example, I want to sum of cost every for every 500 records in real time.
Is it possible to provide batch.size as we provide in consumer config in ksqlDB?
Thanks.
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### Author:  [@mjsax](https://forum.confluent.io/u/mjsax)
#### Post date: [20 April 2022 18:34 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/2 "2022-04-20T18:34:21Z")
ksqlDB does not support count-size windows – only time-size windows.
Maybe you can use an UDF to implement what you need?
> Is it possible to provide batch.size as we provide in consumer config in ksqlDB?
Yes, but it will only impact performance, not semantics. (cf [ksqlDB Server Configuration Parameter Reference - ksqlDB Documentation](https://docs.ksqldb.io/en/latest/reference/server-configuration/#ksqlstreamsproducercompressiontype) – you can set any client config this way)
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### Author:  [@shubhamshirur](https://forum.confluent.io/u/shubhamshirur)
#### Post date: [21 April 2022 04:16 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/3 "2022-04-21T04:16:25Z")
Thanks for your response.
I am getting sales data in JSON format and I want to create array of every 500 messages for one of its fields.
This is what I want to achieve. Yes UDF can help me here, As per my understanding UDF needs to be programmed and converted into jar to add into plugin path if KsqlDB.
But I am using confluent cloud so where shall I put UDF’s jar to leverage it?
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### Author:  [@mjsax](https://forum.confluent.io/u/mjsax)
#### Post date: [21 April 2022 15:27 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/4 "2022-04-21T15:27:10Z")
UDFs are not supported in Confluent Cloud right now ☹
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### Author:  [@shubhamshirur](https://forum.confluent.io/u/shubhamshirur)
#### Post date: [21 April 2022 15:45 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/5 "2022-04-21T15:45:19Z")
So do I left with option of setting up self managed ksqldb pointing to confluent cloud and using UDF on that self managed ksqldb ?
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### Author:  [@mjsax](https://forum.confluent.io/u/mjsax)
#### Post date: [21 April 2022 18:01 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/6 "2022-04-21T18:01:56Z")
Yes, that is for sure an option.
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### Author:  [@system](https://forum.confluent.io/u/system)
#### Post date: [20 May 2022 03:07 UTC](https://forum.confluent.io/t/window-of-message-batch/4821/7 "2022-05-20T03:07:16Z")
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