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From Aaron Morton <aa...@thelastpickle.com>
Subject Re: querying time series from hadoop
Date Tue, 31 Dec 2013 02:11:22 GMT
> So now i will try to patch my cassandra 1.2.11 installation but i just wanted to ask you
guys first, if there is any other solution that does not involve a release.
That patch in CASSANDRA-6311 is for 2.0 you cannot apply it to 1.2

> but when i am using the java driver, the driver already uses row key for token statements
and i cannot execute the query above, therefore it does a full scan of rows.
The  ColumnFamilyRecordReader is designed to read lots of rows, not a single row. 

You should be able to use the java driver from a hadoop task though to read a single row.
Can you provide some more info on what you are doing ? 

Cheers

-----------------
Aaron Morton
New Zealand
@aaronmorton

Co-Founder & Principal Consultant
Apache Cassandra Consulting
http://www.thelastpickle.com

On 26/12/2013, at 9:56 pm, mete <efkarr@gmail.com> wrote:

> Hello  folks, 
> 
> i have come up with a basic time series cql schema based on the articles here:
> 
> http://www.datastax.com/dev/blog/advanced-time-series-with-cassandra
> 
> so simply put its something like:
> 
> rowkey, timestamp, col3, col4 etc... 
> 
> where rowkey and timestamp are compound keys.
> 
> Where i am having issues is to efficiently query this data structure. 
> 
> When i use cqlsh and query it is perfectly fine:
> 
> select * from table where rowkey='row key' and date > xxx and date <= yyy
> 
> but when i am using the java driver, the driver already uses row key for token statements
and i cannot execute the query above, therefore it does a full scan of rows.
> 
> The issue that i am having is discussed here:
> 
> http://stackoverflow.com/questions/19189649/composite-key-in-cassandra-with-pig
> 
> i have gone through the relevant jira issues 6151 and 6311. This behaviour is supposed
to be fixed in 2.0.x but so far it is not there. So now i will try to patch my cassandra 1.2.11
installation but i just wanted to ask you guys first, if there is any other solution that
does not involve a release.
> 
> i assume that this is somewhat a common use case, the articles i referred seems to be
old enough and unless i am missing something obvious i cannot query this schema efficiently
with the current version (1.2.x or 2.0.x)
> 
> Does anyone has a similar issue? Any pointers are welcome.
> 
> Regards
> Mete
> 
> 
> 
> 


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