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From Ashutosh Dhundhara <ashutoshdhundh...@yahoo.com>
Subject Re: Comment on query performance
Date Thu, 29 Dec 2016 10:02:56 GMT
Thanks DuyHai.

One more thing, is it going to be a full table scan across all the nodes in
cluster?

On Thu, Dec 29, 2016 at 3:30 PM, DuyHai Doan <doanduyhai@gmail.com> wrote:

> In your case, ALLOW FILTERING will require Cassandra to scan linearly on
> disk and fetch all the partition data into memory  so the performance
> depends on how "large" your partition is. For small partitions it should be
> fine.
>
>
> On Thu, Dec 29, 2016 at 10:00 AM, Ashutosh Dhundhara <
> ashutoshdhundhara@yahoo.com> wrote:
>
>> Hi All,
>>
>> I have a table like this:
>>
>> CREATE TABLE IF NOT EXISTS Posts (
>>     idObject int,
>>     objectType text,
>>     idParent int,
>>     id int,
>>     idResolution int,
>>     PRIMARY KEY ((idObject, objectType, idParent), id)
>> );
>>
>> Now have a look at the following query:
>>
>> SELECT * FROM POSTS WHERE idobject = 1 AND objectType = 'COURSE' AND idParent = 0
AND idResolution = 1 ALLOW FILTERING
>>
>> Now the Partition Key is completely known, so if I use ALLOW FILTERING is
>> there going to be any performance issue because the filtering is going to
>> be done in a known single partition?
>>
>>
>> --
>> Ashutosh Dhundhara
>>
>
>


-- 
Ashutosh Dhundhara

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