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Hive, mail # user - Partitioning EXTERNAL TABLE without copying or moving files


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Re: Partitioning EXTERNAL TABLE without copying or moving files
Aniket Mokashi 2011-12-09, 02:17
It is a hadoop limitation. hdfs move operation is inexpensive. I am
assuming that is not an option to you because you want to save the path
structure (for some backward compatibility sake).

Something like symbolic links (i think its not supported in 0.20, not sure)
or path filter might help. But, it would be a hack.

Thanks,
Aniket

On Thu, Dec 8, 2011 at 3:59 PM, Jasper Knulst <[EMAIL PROTECTED]>wrote:

> Hi Vince,
>
> Hive partitioning can only exist by issueing new directories in HDFS.
> There is no way to partition the data in a Hive table without adding extra
> filepaths/dirs in HDFS.
>
> For an external table you have to redistribute the data yourself in
> corresponding filepaths and add the new partition based on that by editing
> the Hive metadata.
>
> Cheers Jasper
> Op 8 dec. 2011 21:47 schreef "Vince Hoang" <[EMAIL PROTECTED]> het
> volgende:
>
>   Hi,
>>
>>  I am running Hive 0.7.0 with Hadoop 0.20.2.  I have one HDFS folder
>> full of web server logs dated back several months.
>>
>>  Is possible to partition an EXTERNAL TABLE without copying/moving files
>> or altering the layout of the directory?
>>
>>  For example, in HDFS, I have:
>>
>>  > /logs/log-2011-09-01
>>  > /logs/log-2011-09-02
>>  >   …
>>  > /logs/log-2011-12-01
>>
>>  I'd like to know if it's possible to partition the EXTERNAL TABLE by
>> date without having to create subdirectories:
>>
>>  > /logs/2011-09-01/log-2011-09-01
>>  > /logs/2011-09-02/log-2011-09-02
>>  >   …
>>  > /logs/2011-12-01/log-2011-12-01
>>
>>  Is it possible?
>>
>>   Thanks,
>> Vince
>>
>>
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