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From Sávio Teles <savio.te...@lupa.inf.ufg.br>
Subject Re: How to perform range queries efficiently?
Date Mon, 02 Sep 2013 19:13:00 GMT
> We performed some modifications and created another column family, which
> maps the secondary index to the key of the original column family. The
> improvements were very impressive in our case!


Sorry, I coundn't understand! What changes? Have you built a B-tree?


2013/9/2 Francisco Nogueira Calmon Sobral <fsobral@igcorp.com.br>

> We had some problems when using secondary indexes because of three issues:
>
> - The query is a Range Query, which means that it is slow.
> - There is an open bug regarding the use of row cache for secondary
> indexes (CASSANDRA-4973)
> - The cardinality of our secondary key was very low (this was bad)
>
> We performed some modifications and created another column family, which
> maps the secondary index to the key of the original column family. The
> improvements were very impressive in our case!
>
> Best regards
> Francisco
>
>
> On Aug 28, 2013, at 12:22 PM, Vivek Mishra <mishra.vivs@gmail.com> wrote:
>
> Create a column family of compositeType (or PRIMARY KEY) as (user_id,age,
> salary).
>
> Then you will be able to query use eq operator  over partition key and as
> well over clustering key:
>
> You may also exclude salary as a secondary index rather than part of
> cluster key(e.g. age,salary)
>
> I am sure based on your query usage, you can opt for either a composite
> key or may mix composite key with secondary index !
>
> Have a look at:
> http://www.datastax.com/dev/blog/introduction-to-composite-columns-part-1
>
> Hope it helps.
>
>
> -Vivek
>
>
> On Wed, Aug 28, 2013 at 5:49 PM, Sávio Teles <savio.teles@lupa.inf.ufg.br>wrote:
>
>> I can populate again. We are modelling the data yet! Tks.
>>
>>
>> 2013/8/28 Vivek Mishra <mishra.vivs@gmail.com>
>>
>>> Just saw that you already have data populated, so i guess modifying for
>>> composite key may not work for you.
>>>
>>> -Vivek
>>>
>>>
>>> On Tue, Aug 27, 2013 at 11:55 PM, Sávio Teles <
>>> savio.teles@lupa.inf.ufg.br> wrote:
>>>
>>>> Vivek, using a composite key, how would be the query?
>>>>
>>>>
>>>> 2013/8/27 Vivek Mishra <mishra.vivs@gmail.com>
>>>>
>>>>> For such queries, looks like you may create a composite key as
>>>>> (user_id,age, salary).
>>>>>
>>>>> Too much indexing always kills(irrespective of RDBMS or NoSQL).
>>>>> Remember every search request on secondary indexes will be passed on
each
>>>>> node in ring.
>>>>>
>>>>> -Vivek
>>>>>
>>>>>
>>>>> On Tue, Aug 27, 2013 at 11:11 PM, Sávio Teles <
>>>>> savio.teles@lupa.inf.ufg.br> wrote:
>>>>>
>>>>>> Use a database that is designed for efficient range queries? ;D
>>>>>>>
>>>>>>
>>>>>> Is there no way to do this with Cassandra? Like using Hive, Sorl...
>>>>>>
>>>>>>
>>>>>> 2013/8/27 Robert Coli <rcoli@eventbrite.com>
>>>>>>
>>>>>>> On Fri, Aug 23, 2013 at 5:53 AM, Sávio Teles <
>>>>>>> savio.teles@lupa.inf.ufg.br> wrote:
>>>>>>>
>>>>>>>> I need to perform range query efficiently.
>>>>>>>>
>>>>>>> ...
>>>>>>>
>>>>>>>> This query takes a long time to run. Any ideas to perform
it
>>>>>>>> efficiently?
>>>>>>>>
>>>>>>>
>>>>>>> Use a database that is designed for efficient range queries?
;D
>>>>>>>
>>>>>>> =Rob
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Atenciosamente,
>>>>>> Sávio S. Teles de Oliveira
>>>>>> voice: +55 62 9136 6996
>>>>>> http://br.linkedin.com/in/savioteles
>>>>>>  Mestrando em Ciências da Computação - UFG
>>>>>> Arquiteto de Software
>>>>>> Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Atenciosamente,
>>>> Sávio S. Teles de Oliveira
>>>> voice: +55 62 9136 6996
>>>> http://br.linkedin.com/in/savioteles
>>>>  Mestrando em Ciências da Computação - UFG
>>>> Arquiteto de Software
>>>> Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG
>>>>
>>>
>>>
>>
>>
>> --
>> Atenciosamente,
>> Sávio S. Teles de Oliveira
>> voice: +55 62 9136 6996
>> http://br.linkedin.com/in/savioteles
>>  Mestrando em Ciências da Computação - UFG
>> Arquiteto de Software
>> Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG
>>
>
>
>


-- 
Atenciosamente,
Sávio S. Teles de Oliveira
voice: +55 62 9136 6996
http://br.linkedin.com/in/savioteles
Mestrando em Ciências da Computação - UFG
Arquiteto de Software
Laboratory for Ubiquitous and Pervasive Applications (LUPA) - UFG

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