Tumbling window per key

[Navneeth Krishnan]

Hi All,

I was looking at the documentation for windows and got a little confused. As per my understanding tumbling window per key will create a non overlapping window based on when the data for that key arrived. For example consider a tumbling window of 30 seconds

user1 - 10:01:01

user2 - 10:01:02

user1 - 10:01:05

user2 - 10:01:06

user2 - 10:01:08

Result:

user1 (10:01:01 & 10:01:05)

user2 (10:01:02 & 10:01:06)

user2 (10:01:08)

Is this the right understanding?

But as per the below image in docs, it looks like the window is not per key, please correct me if i'm wrong.

Thanks

[Arvid Heise-3]

Hi Navneeth,

Your understanding is correct.

In the image, all windows across the keys for the same timespan are grouped together, which make sense from a logical perspective as you would talk about the first, second, ... window.

But technically, there are 15 small windows involved instead of the depicted 5 windows. I guess, for you, the technical representation would be easier to understand.

For session windows, for example, only the technical view makes sense. So you could also look at examples of these windows if it's easier for you.

On Tue, May 12, 2020 at 10:05 AM Navneeth Krishnan <[hidden email]> wrote:

Hi All,

I was looking at the documentation for windows and got a little confused. As per my understanding tumbling window per key will create a non overlapping window based on when the data for that key arrived. For example consider a tumbling window of 30 seconds

user1 - 10:01:01

user2 - 10:01:02

user1 - 10:01:05

user2 - 10:01:06

user2 - 10:01:08

Result:

user1 (10:01:01 & 10:01:05)

user2 (10:01:02 & 10:01:06)

user2 (10:01:08)

Is this the right understanding?

But as per the below image in docs, it looks like the window is not per key, please correct me if i'm wrong.

Thanks

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