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Pig >> mail # user >> Best Practice: store depending on data content


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Re: Best Practice: store depending on data content
I am not aware of any work on adding those features to MultiStorage.

I think the best way to do this is to use Hcatalog. (It makes the hive
metastore available for all of hadoop, so you get metadata for your data
as well).
You can associate a outputformat+serde for a table (instead of file name
ending), and HCatStorage will automatically pick the right format.

Thanks,
Thejas
On 6/28/12 2:17 AM, Markus Resch wrote:
> Thanks Thejas,
>
> This _really_ helped a lot :)
> Some additional question on this:
> As far as I see, the MultiStorage is currently just capable to write CSV
> output, right? Is there any attempt ongoing currently to make this
> storage more generic regarding the format of the output data? For our
> needs we would require AVRO output as well as some special proprietary
> binary encoding for which we already created our own storage. I'm
> thinking about a storage that will select a certain writer method
> depending to the file names ending.
>
> Do you know of such efforts?
>
> Thanks
>
> Markus
>
>
> Am Freitag, den 22.06.2012, 11:23 -0700 schrieb Thejas Nair:
>> You can use MultiStorage store func -
>> http://pig.apache.org/docs/r0.9.1/api/org/apache/pig/piggybank/storage/MultiStorage.html
>>
>> Or if you want something more flexible, and have metadata as well, use
>> hcatalog . Specify the keys on which you want to partition as your
>> partition keys in the table. Then use HcatStorer() to store the data.
>> See http://incubator.apache.org/hcatalog/docs/r0.4.0/index.html
>>
>> Thanks,
>> Thejas
>>
>>
>>
>> On 6/22/12 4:54 AM, Markus Resch wrote:
>>> Hey everyone,
>>>
>>> We're doing some aggregation. The result contains a key where we want to
>>> have a single output file for each key. Is it possible to store files
>>> like this? Especially adjusting the path by the key's value.
>>>
>>> Example:
>>> Input = LOAD 'my/data.avro' USING AvroStorage;
>>> [.... doing stuff....]
>>> Output = GROUP AggregatesValues BY Key;
>>> FOREACH Output Store * into
>>> '/my/output/path/by/$Output.Key/Result.avro'
>>>
>>> I know this example does not work. But is there anything similar
>>> possible? And, as I assume, not: is there some framework in the hadoop
>>> world that can do such stuff?
>>>
>>>
>>> Thanks
>>>
>>> Markus
>>>
>>>
>
>