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From Raj N <raj.cassan...@gmail.com>
Subject Re: Storing bi-temporal data in Cassandra
Date Sat, 14 Feb 2015 23:05:05 GMT
I don't think thats solves my problem. The question really is why can't we
use ranges for both time columns when they are part of the primary key.
They are on 1 row after all. Is this just a CQL limitation?

-Raj

On Sat, Feb 14, 2015 at 3:35 AM, DuyHai Doan <doanduyhai@gmail.com> wrote:

> "I am trying to get the state as of a particular transaction_time"
>
>  --> In that case you should probably define your primary key in another
> order for clustering columns
>
> PRIMARY KEY (weatherstation_id,transaction_time,event_time)
>
> Then, select * from temperatures where weatherstation_id = 'foo' and
> event_time >= '2015-01-01 00:00:00' and event_time < '2015-01-02
> 00:00:00' and transaction_time = 'xxxx'
>
>
>
> On Sat, Feb 14, 2015 at 3:06 AM, Raj N <raj.cassandra@gmail.com> wrote:
>
>> Has anyone designed a bi-temporal table in Cassandra? Doesn't look like I
>> can do this using CQL for now. Taking the time series example from well
>> known modeling tutorials in Cassandra -
>>
>> CREATE TABLE temperatures (
>> weatherstation_id text,
>> event_time timestamp,
>> temperature text,
>> PRIMARY KEY (weatherstation_id,event_time),
>> ) WITH CLUSTERING ORDER BY (event_time DESC);
>>
>> If I add another column transaction_time
>>
>> CREATE TABLE temperatures (
>> weatherstation_id text,
>> event_time timestamp,
>> transaction_time timestamp,
>> temperature text,
>> PRIMARY KEY (weatherstation_id,event_time,transaction_time),
>> ) WITH CLUSTERING ORDER BY (event_time DESC, transaction_time DESC);
>>
>> If I try to run a query using the following CQL, it throws an error -
>>
>> select * from temperatures where weatherstation_id = 'foo' and event_time
>> >= '2015-01-01 00:00:00' and event_time < '2015-01-02 00:00:00' and
>> transaction_time < '2015-01-02 00:00:00'
>>
>> It works if I use an equals clause for the event_time. I am trying to get
>> the state as of a particular transaction_time
>>
>> -Raj
>>
>
>

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