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From Chamila Wijayarathna <cdwijayarat...@gmail.com>
Subject Re: Understanding what is key and partition key
Date Tue, 16 Dec 2014 13:54:33 GMT
Hi Jens,

Thank You!

On Tue, Dec 16, 2014 at 7:03 PM, Jens Rantil <jens.rantil@tink.se> wrote:
>
> For the first row, the key is: (2014, N, 1, සියළුම, යුද්ධ) and
the
> value-part is (664).
>
> Cheers,
> Jens
>
> ——— Jens Rantil Backend engineer Tink AB Email: jens.rantil@tink.se
> Phone: +46 708 84 18 32 Web: www.tink.se Facebook Linkedin Twitter
>
>
> On Tue, Dec 16, 2014 at 2:25 PM, Chamila Wijayarathna <
> cdwijayarathna@gmail.com> wrote:
>
>> Hi Jack,
>>
>> So what will be the keys and values of the following CF instance?
>>
>>  year | category | frequency | word1            | word2       | id
>> ------+----------+-----------+------------------+-------------+-------
>>  2014 |        N |         1 |            සියළුම |         යුද්ධ
|   664
>>  2014 |        N |         1 |            එච් |       කාණ්ඩය |
12526
>>  2014 |        N |         1 |            ගජබා |     සුපර්ක්‍රොස්
| 25779
>>  2014 |        N |         1 |              බී|       කාණ්ඩය | 12505
>>
>> Thank You!
>>
>> On Tue, Dec 16, 2014 at 6:45 PM, Jack Krupansky <jack@basetechnology.com>
>> wrote:
>>>
>>>   Correction: year and category form a “composite partition key”.
>>>
>>> frequency, word1, and word2 are “clustering columns”.
>>>
>>> The combination of a partition key with clustering columns is a
>>> “compound primary key”.
>>>
>>> Every CQL row will have a partition key by definition, and may
>>> optionally have clustering columns.
>>>
>>> “The key” should just be a synonym for “primary key”, although sometimes
>>> people are loosely speaking about “the partition” (which should be “the
>>> partition key”) rather than the CQL “row”.
>>>
>>> -- Jack Krupansky
>>>
>>>  *From:* Chamila Wijayarathna <cdwijayarathna@gmail.com>
>>>  *Sent:* Tuesday, December 16, 2014 8:03 AM
>>>  *To:* user@cassandra.apache.org
>>>  *Subject:* Understanding what is key and partition key
>>>
>>>   Hello all,
>>>
>>> I have read a lot about Cassandra and I read about key-value pairs,
>>> partition keys, clustering keys, etc..
>>> Is key mentioned in key-value pair and partition key refers to same or
>>> are they different?
>>>
>>>
>>> CREATE TABLE corpus.bigram_time_category_ordered_frequency (
>>>     id bigint,
>>>     word1 varchar,
>>>     word2 varchar,
>>>     year int,
>>>     category varchar,
>>>     frequency int,
>>>     PRIMARY KEY((year, category),frequency,word1,word2));
>>>
>>>
>>> In this schema, I know (year, category) is the compound partition key
>>> and frequency is the clustering key. What is the key here?
>>>
>>>
>>> Thank You!
>>>
>>> --
>>> *Chamila Dilshan Wijayarathna,*
>>> SMIEEE, SMIESL,
>>> Undergraduate,
>>> Department of Computer Science and Engineering,
>>> University of Moratuwa.
>>>
>>
>>
>> --
>> *Chamila Dilshan Wijayarathna,*
>> SMIEEE, SMIESL,
>> Undergraduate,
>> Department of Computer Science and Engineering,
>> University of Moratuwa.
>>
>
>

-- 
*Chamila Dilshan Wijayarathna,*
SMIEEE, SMIESL,
Undergraduate,
Department of Computer Science and Engineering,
University of Moratuwa.

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