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From Jon Haddad <...@jonhaddad.com>
Subject Re: New column
Date Mon, 19 Aug 2019 21:21:39 GMT
It'll be about the same overhead as selecting the entire partition, since
that's essentially what you're doing.

I created a tlp-stress workload this morning but haven't merged it into
master yet.  I need to do a little cleanup and I might tweak it a little,
but if you're feeling adventurous you can build the branch yourself:
https://github.com/thelastpickle/tlp-stress/tree/jon/106-allow-filtering-workload

Once you do an in place build (./gradlew shadowJar), you'll probably want
to do something like the following:

bin/tlp-stress run AllowFiltering -p 1k -d 1h -r .5 --populate 1m
--field.allow_filtering.payload='random(100,200)' --compaction lcs

That's running against C* on my laptop.  Here's what all those arguments do:

-p 1k # 1000 partitions
-d 1h # run for 1 hour (-d = duration)
-r .5  # (50% reads)
--populate 1m # (pre populate with 1 million rows)
--field.allow_filtering.payload='random(100,200)'  # use 100 - 200 bytes
for the payload.  I assume there will be other data other than just the
record, this will let you size each row accordingly
--compaction lcs # use leveled compaction

You can tweak the params as needed.  If you've got a cluster up, use the
--host to point to it.    If you don't have a cluster up, you can spin one
up in AWS in about 5-10 minutes using our tools:
https://thelastpickle.com/tlp-cluster/

Happy testing!
Jon


On Mon, Aug 19, 2019 at 1:23 PM Rahul Reddy <rahulreddy1234@gmail.com>
wrote:

> Jon,
>
> If we expect non of  our partition key to have more than 100 records and
> pass partition key in where clause we wouldnt see issues using new column
> and allow filtering?  Can you please point me to any doc how allow
> filtering works. I was in assumption of it goes through all the partitions
>
>
> On Sun, Aug 18, 2019, 4:33 PM Jon Haddad <jon@jonhaddad.com> wrote:
>
>> If you're giving the partition key you won't scan the whole table. The
>> overhead will depend on the size or the partition.
>>
>> Would be an interesting workload for our tlp-stress tool, I'll code
>> something up for the next release.
>>
>> On Sun, Aug 18, 2019, 12:58 PM Rahul Reddy <rahulreddy1234@gmail.com>
>> wrote:
>>
>>> Hello,
>>>
>>> We have a table and want to add column and select based on existing
>>> entire primary key plus new column using allow filtering. Since my where
>>> clause has all the primary key + new column does the allow filtering scan
>>> only the partions which are listed or does it has to scan whole table? What
>>> is the best approach add new column and query it based on existing primary
>>> key plus new column?
>>>
>>

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