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From Devopam Mittra <devo...@gmail.com>
Subject Re: Performance impact with ALLOW FILTERING clause.
Date Sun, 18 Aug 2019 00:55:23 GMT
Hi Asad,
Seems to me that your development team will need to remodel the tables
sooner than later. This problem can't be left unattended for long once it
starts hitting severely.
The way Cassandra is, you may want to have them replicate the same table
with different PK / structure to suitably embed a WHERE clause in the base
query if nothing else works out.

Allow filtering is best avoided for routine queries or at max good for
ad-hoc analysis not involving arithmetic operation (like count/sum) .

Regards
Devopam


On Thu, Jul 25, 2019, 7:19 PM ZAIDI, ASAD A <az192g@att.com> wrote:

> Hello Folks,
>
>
>
> I was going thru documentation and saw at many places saying ALLOW
> FILTERING causes performance unpredictability.  Our developers says ALLOW
> FILTERING clause is implicitly added on bunch of queries by spark-Cassandra
>  connector and they cannot control it; however at the same time we see
> unpredictability in application performance – just as documentation says.
>
>
>
> I’m trying to understand why would a connector add a clause in query when
> this can cause negative impact on database/application performance. Is that
> data model that is driving connector make its decision and add allow
> filtering to query automatically or if there are other reason this clause
> is added to the code. I’m not a developer though I want to know why
> developer don’t have any control on this to happen.
>
>
>
> I’ll appreciate your guidance here.
>
>
>
> Thanks
>
> Asad
>
>
>
>
>

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