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From Franc Carter <franc.car...@sirca.org.au>
Subject Re: data model advice
Date Fri, 24 Feb 2012 04:40:20 GMT
On Fri, Feb 24, 2012 at 2:54 PM, Martin Arrowsmith <
arrowsmith.martin@gmail.com> wrote:

> Hi Franc,
>
> Or, you can consider using composite columns. It is not recommended to use
> Super Columns anymore.
>
> Best wishes,
>

On first read it would seem that there is fair bit of overhead with
composite columns as it's my understanding that the column name is stored
with each value - or have I missed something ?

cheers


>
> Martin
>
>
> On Thu, Feb 23, 2012 at 7:51 PM, Indranath Ghosh <indranathg@gmail.com>wrote:
>
>> How about using a composite row key like the following:
>>
>> Entity.Day1.TypeA: {col1:val1, col2:val2, . . . }
>> Entity.Day1.TypeB: {col1:val1, col2:val2, . . . }
>> .
>> .
>> Entity.DayN.TypeA: {col1:val1, col2:val2, . . . }
>> Entity.DayN.TypeB: {col1:val1, col2:val2, . . . }
>>
>> It is better to avoid super columns..
>>
>> -indra
>>
>> On Thu, Feb 23, 2012 at 6:36 PM, Franc Carter <franc.carter@sirca.org.au>wrote:
>>
>>>
>>> Hi,
>>>
>>> I've finished my first model and experiments with Cassandra with result
>>> I'm pretty happy with - so I thought I'd move on to something harder.
>>>
>>> We have a set of data that has a large number of entities (which is our
>>> primary search key), for each of the entities we have a smallish (<100)
>>> number of sets of data. Each set has a further set the contains column/vale
>>> pairs.
>>>
>>> The queries will be for an Entity, for one or more days for one or more
>>> of the subsets. Conceptually I would like to model like it like this:-
>>>
>>> Entity {
>>>    Day1: {
>>>        TypeA: {col1:val1, col2:val2, . . . }
>>>        TypeB: {col1:val1, col3:val3, . . . }
>>>           .
>>>           .
>>>    }
>>>    .
>>>    .
>>>    .
>>>    DayN: {
>>>        TypeB: {col3:val3, col5:val5, . . . }
>>>        TypeD: {col3:val3, col6:val6, . . . }
>>>           .
>>>           .
>>>    }
>>> }
>>>
>>> My understanding of the Cassandra data model is that I run out of
>>> map-dept to do this in my simplistic approach as the Days are super
>>> columns, the types are column and then I don't have a col/val map left for
>>> data.
>>>
>>> Does anyone have advice on a good approach ?
>>>
>>> thanks
>>>
>>> --
>>>
>>> *Franc Carter* | Systems architect | Sirca Ltd
>>>  <marc.zianideferranti@sirca.org.au>
>>>
>>> franc.carter@sirca.org.au | www.sirca.org.au
>>>
>>> Tel: +61 2 9236 9118
>>>
>>> Level 9, 80 Clarence St, Sydney NSW 2000
>>>
>>> PO Box H58, Australia Square, Sydney NSW 1215
>>>
>>>
>>
>>
>> --
>> *Indranath Ghosh
>> Phone: 408-813-9207*
>>
>>
>


-- 

*Franc Carter* | Systems architect | Sirca Ltd
 <marc.zianideferranti@sirca.org.au>

franc.carter@sirca.org.au | www.sirca.org.au

Tel: +61 2 9236 9118

Level 9, 80 Clarence St, Sydney NSW 2000

PO Box H58, Australia Square, Sydney NSW 1215

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