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From aaron morton <aa...@thelastpickle.com>
Subject Re: Why CQL returns data in byte format, while Hive de-serialize and return the data in readable format
Date Mon, 11 Feb 2013 19:20:50 GMT
I suggest trying Int32Type and Double http://www.datastax.com/docs/datastax_enterprise2.1/analytics/about_hive#mapping-hive-external-tables-to-cassandra-column-families

Cheers

-----------------
Aaron Morton
Freelance Cassandra Developer
New Zealand

@aaronmorton
http://www.thelastpickle.com

On 8/02/2013, at 10:13 PM, Dinusha Dilrukshi <sdddilrukshi@gmail.com> wrote:

> 
> [1] If we insert the data using CQL and retrieve using CQL then it returns readable data.
(not byte type).
> [2] If we insert the data using hive query and retrieve using hive query, it also returns
readable data. (not byte type.) 
> [3] Only if we insert data using hive query and then retrieve the data using CQL, then
it returns byte type.
> 
> How data serialization/de-serialization happens in Cassandra. Why [3] returns data in
byte format, while same data returns true hive query is not in byte type ?
> 
> Regards,
> Dinusha.
> 
> 
> 
> On Fri, Feb 8, 2013 at 8:39 AM, Edward Capriolo <edlinuxguru@gmail.com> wrote:
> In cql3 a column must be all the same type . Since cql transposes columns the only thing
they can be is byte array. Cql2 is better at compact tables in. This regard.
> 
> 
> On Thursday, February 7, 2013, Dinusha Dilrukshi wrote:
> Hi,
> 
> We are using same underlying column family and extract the data using Hive query and
CQL query. 
> Column family meta data contains Comparator='IntegerType'  and default_validation_class
= FloatType.
> 
> CREATE COLUMN FAMILY cpu_avg_5min 
> WITH COMPARATOR = 'IntegerType' 
>  AND key_validation_class = UTF8Type 
>  AND default_validation_class = FloatType;  
> 
> Queering through Hive using a Hive query returns readable data while queering using CQL
returns byte format.
> 
> Hive query result:
> localhost:8282 1350465600 71.0 
> localhost:8282 1350466500 69.0 
> 
> CQL query result:
>  localhost:8282 | 232340574229062120517680 | 1.0561e-05 
>  localhost:8282 | 232340574229062137229360 | 2.7594e-06 
> 
> Can someone explains the above behavior ?
> 
> Regards,
> DInusha.
> 


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