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From Les Hartzman <lhartz...@gmail.com>
Subject Re: Wide rows (time series data) and ORM
Date Wed, 23 Oct 2013 17:11:30 GMT
Hi Vivek,

What I'm looking for are a couple of things as I'm gaining an understanding
of Cassandra. With wide rows and time series data, how do you (or can you)
handle this data in an ORM manner? Now I understand that with CQL3, doing a
"select * from time_series_data" will return the data as multiple rows. So
does handling this data equal the way you would deal with any mapping of
objects to results in a relational manner? Would you still use a JPA
approach or is there a Cassandra/CQL3-specific way of interacting with the
database?

I expect to use a compound key for partitioning/clustering. For example I'm
planning on creating a table as follows:
              CREATE TABLE sensor_data (
                            sensor_id               text,
                            date                       text,
                            data_time_stamp    timestamp,
                            reading                  int,
                            PRIMARY KEY ( (sensor_id, date),
data_time_stamp) );
The 'date' field will be day-specific so that for each day there will be a
new row created.

So will I be able to define a POJO, SensorData, with the fields show above
and basically process each 'row' returned by CQL as another SensorData
object?

Thanks.

Les



On Wed, Oct 23, 2013 at 1:22 AM, Vivek Mishra <mishra.vivs@gmail.com> wrote:

> Can Kundera work with wide rows in an ORM manner?
>
> What specifically you looking for? Composite column based implementation
> can be built using Kundera.
> With Recent CQL3 developments, Kundera supports most of these. I think
> POJO needs to be aware of number of fields needs to be persisted(Same as
> CQL3)
>
> -Vivek
>
>
> On Wed, Oct 23, 2013 at 12:48 AM, Les Hartzman <lhartzman@gmail.com>wrote:
>
>> As I'm becoming more familiar with Cassandra I'm still trying to shift my
>> thinking from relational to NoSQL.
>>
>> Can Kundera work with wide rows in an ORM manner? In other words, can you
>> actually design a POJO that fits the standard recipe for JPA usage? Would
>> the queries return collections of the POJO to handle wide row data?
>>
>> I had considered using Spring and JPA for Cassandra, but it appears that
>> other than basic configuration issues for Cassandra, to use Spring and JPA
>> on a Cassandra database seems like an effort in futility if Cassandra is
>> used as a NoSQL database instead of mimicking an RDBMS solution.
>>
>> If anyone can shed any light on this, I'd appreciate it.
>>
>> Thanks.
>>
>> Les
>>
>>
>

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