Home | About | Sematext search-lucene.com search-hadoop.com
 Search Hadoop and all its subprojects:

Switch to Threaded View
Hive, mail # user - Hive to read sequencefile


Copy link to this message
-
Re: Hive to read sequencefile
Edward Capriolo 2012-07-10, 00:53
yes you need an input format. I have one that turns key plus value to a
pairwritable

On Monday, July 9, 2012, Daning Wang <[EMAIL PROTECTED]> wrote:
> Thanks Navis.
>
> The problem is that the key and value are custom classes. e.g, key is
class A, and value is class B. we want to show certain data in Class A and
B from getters. so we do need a SerDe to deserialize the data.
>
> Since SerDe interface can only pass one parameter, so I need to write a
InputFormat to combine key and value to one object, right?
>
>     public Object deserialize(Writable arg0) throws SerDeException {
>
>
> Daning
>
>
>
>
> On Mon, Jul 9, 2012 at 4:56 PM, Navis류승우 <[EMAIL PROTECTED]> wrote:
>>
>> You can try 'STORED AS SEQUENCEFILE' when creating table.
>>
https://cwiki.apache.org/Hive/languagemanual-ddl.html#LanguageManualDDL-Create%252FDropTable
>>
>>
>> 2012/7/10 Daning Wang <[EMAIL PROTECTED]>
>>>
>>> Hi all,
>>>
>>> New to here. I have sequence files  and I want to read in Hive, I did
some search on the net. looks the way I need to do
>>>
>>> 1. Write new FileInputFormat so Hive can read both key and value.
>>> (ref http://osdir.com/ml/hive-user-hadoop-apache/2009-10/msg00034.html)
>>>
>>> 2. Write a SerDe to deserialize custom class data for key and value in
sequence file, I don't need serialize.
>>>
>>> Is this the right way to do? any simple way to do this?
>>>
>>> Thanks,
>>>
>>> Daning
>>
>
>