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From Aaron Morton <aa...@thelastpickle.com>
Subject Re: Hadoop Word Count Super Column Example?
Date Wed, 20 Oct 2010 19:08:55 GMT
We're the IColumn objects passed to the map function o.a.c.db.SuperColumn instances ? 

A


On 21 Oct, 2010,at 02:48 AM, Jeremy Hanna <jeremy.hanna1234@gmail.com> wrote:

> Have your tried it ?


yes, with a modified word count example a month or so ago.

On Oct 20, 2010, at 3:27 AM, aaron morton wrote:

> My understanding of the Hadoop integration is not great but from what I can see. The
code in o.a.c.hadoop.ColumnFamilyRecordReader does not use a super_column in the ColumnParent
struct when making the get_range_slices() call. It's just using the ColumnFamily. 
> 
> So I would guess it would include super columns if they were present. And that the IColumns
passed to your map function will be instances of o.a.c.db.SuperColumn. 
> 
> Have your tried it ?
> 
> Aaron
> 
> 
> 
> On 20 Oct 2010, at 04:44, Jeremy Hanna wrote:
> 
>> It's relatively straightforward, the current mapper gets a map of column names to
IColumns. The SuperColumn implements the IColumn interface. So you would probably need both
the super column name and the subcolumn name to get at it, but you just need to cast the IColumn
to a super column and handle it from there.
>> 
>> On Oct 19, 2010, at 10:31 AM, Frank LoVecchio wrote:
>> 
>>> I have a Hadoop installation working with a cluster of 0.7 Beta 2 Nodes, and
got the WordCount example to work using the standard configuration. I have been inserting
data into a Super Column (Sensor) with TimeUUID as the compare type, it looks like this:
>>> 
>>> get Sensor['DeviceID:Sensor']
>>> => (super_column=795a4da0-d8ac-11df-9a2c-12313d06187c,
>>> (column=sub_sensor1, value=39.742538, timestamp=1287182112633000) 
>>> (column=sub_sensor2, value=-104.912474, timestamp=1287182112633000) 
>>> (column=mac_address, value=DEADBEEFFEED, timestamp=1287182112633000)) 
>>> 
>>> Is there a Word Count example for super columns? I am trying to count the number
of occurrences of "DEADBEEFFEED", much like "word1" in the column example. 
>>> 
>>> Thanks,
>>> 
>>> Frank LoVecchio
>>> Software Engineer, Isidorey LLC
>>> isidorey.com
>>> 
>>> franklovecchio.com
>>> rodsandricers.com
>> 
> 


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