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From aaron morton <aa...@thelastpickle.com>
Subject Re: Timeseries data
Date Thu, 28 Mar 2013 03:20:42 GMT
sstablekey can help you find which sstables your keys are in. 

But yes, a slice call will need to read from all sstables the row has a fragment in. This
is one reason we normally suggest partitioning time series data by month or year or something
sensible in your problem domain. 

You will probably also want to use reversed comparators so you do not have to use reversed
in your query. 

Hope that helps. 

-----------------
Aaron Morton
Freelance Cassandra Consultant
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 28/03/2013, at 8:25 AM, Bryan Talbot <btalbot@aeriagames.com> wrote:

> In the worst case, that is possible, but compaction strategies try to minimize the number
of SSTables that a row appears in so a row being in ALL SStables is not likely for most cases.
> 
> -Bryan
> 
> 
> 
> On Wed, Mar 27, 2013 at 12:17 PM, Kanwar Sangha <kanwar@mavenir.com> wrote:
> Hi – I have a query on Read with Cassandra. We are planning to have dynamic column
family and each column would be on based a timeseries. 
> 
>  
> 
> Inserting data — key => ‘xxxxxxx′, {column_name => TimeUUID(now), :column_value
=> ‘value’ }, {column_name => TimeUUID(now), :column_value => ‘value’ },…………..
> 
>  
> 
> Now this key might be spread across multiple SSTables over a period of days. When we
do a READ query to fetch say a slice of data from this row based on time X->Y , would it
need to get data from ALL sstables ?
> 
>  
> 
> Thanks,
> 
> Kanwar
> 
>  
> 
> 


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