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From Indranath Ghosh <indrana...@gmail.com>
Subject Re: data model advice
Date Fri, 24 Feb 2012 03:51:38 GMT
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*

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