TWCS target number of time windows

[Oleksandr Shulgin <ol...@zalando.de>]

Hi,

In the TWCS readme[1] it says:


You should target fewer than 50 buckets per table based on your TTL.


What is this recommendation based upon?  The docs from Datastax[2], for
example do not mention anything like that.

Is the recommendation still actual today for the version 3.0.$latest?  What
is the computation complexity behind it: is it N, N*log(N) or N^2, etc.?

Thank you.

[1] https://github.com/jeffjirsa/twcs
[2]
https://docs.datastax.com/en/archived/cassandra/3.0/cassandra/dml/dmlHowDataMaintain.html#dmlHowDataMaintain__twcs

-- 
Alex

Re: TWCS target number of time windows

[Oleksandr Shulgin <ol...@zalando.de>]

On Wed, Aug 21, 2019 at 1:47 PM Jeff Jirsa <jj...@gmail.com> wrote:

> Wild ass guess based on what worked for my previous employer (for whom I
> wrote twcs), but note that if you model it such that partitions are
> contained to a single window/sstable that number is probably irrelevant and
> may be able to be made arbitrarily high
>

Thanks for the instant answer, Jeff! :-)

--
Alex

Re: TWCS target number of time windows

[Jeff Jirsa <jj...@gmail.com>]

Wild ass guess based on what worked for my previous employer (for whom I wrote twcs), but note that if you model it such that partitions are contained to a single window/sstable that number is probably irrelevant and may be able to be made arbitrarily high 

> On Aug 21, 2019, at 4:48 PM, Oleksandr Shulgin <ol...@zalando.de> wrote:
> 
> Hi,
> 
> In the TWCS readme[1] it says:
> 
> You should target fewer than 50 buckets per table based on your TTL.
> 
> What is this recommendation based upon?  The docs from Datastax[2], for example do not mention anything like that.
> 
> Is the recommendation still actual today for the version 3.0.$latest?  What is the computation complexity behind it: is it N, N*log(N) or N^2, etc.?
> 
> Thank you.
> 
> [1] https://github.com/jeffjirsa/twcs
> [2] https://docs.datastax.com/en/archived/cassandra/3.0/cassandra/dml/dmlHowDataMaintain.html#dmlHowDataMaintain__twcs
> 
> -- 
> Alex
>