Hi Anoop,
Thanks a lot for the explanation.
Need to go through the documentation properly…. ;-)
Cheers,
Subroto Sanyal
On Jun 14, 2012, at 10:15 AM, Anoop Sam John wrote:
> Hi Subroto
> Scan.addColumn you can use when u want only specific columns to be
> retrieved in the sacn . U can read the javadoc in addColumn() and addFamily()
> methods and then it will be clear.
> scan.addColumn(Bytes.toBytes(column), Bytes.toBytes(""))
> As you do this empty qualifier name is getting added in the family list which
> needs to be retrieved.
>
> So if you want to retrieve whole data avoid addColumn and addFamily.
> If want want specific CFs to be retrieved go with addFamily
> Within a CF u want specific qualifier only then only go for addColumn
>
> -Anoop-
> ________________________________________
> From: Subroto [[email protected]]
> Sent: Thursday, June 14, 2012 1:35 PM
> To: [email protected]
> Subject: Re: TableRecordReaderImpl is not able to get the rows
>
> Hi Sonal,
>
> Thanks for your suggestion… I checked my code and found out that I was doing
> something like this:
> for (String column : columns) {
> scan.addColumn(Bytes.toBytes(column), Bytes.toBytes(""))
> }
>
> The same scan object was being set in the configuration. After removing this
> piece of code, the MR Job worked fine.
>
> One more doubt:
> Scan.addColumn takes two argument:
> public Scan addColumn(byte[] family,
> byte[] qualifier)
> The first one is the column name in bytes. What should be passed as second
> argument if I want the qualifier to be ignored(I mean to include any
> qualifier)???
> My HBase table looks like this:
> ROW
> COLUMN+CELL
> row1
> column=cf:a, timestamp=1339581548508, value=value1
> row2
> column=cf:b, timestamp=1339581557585, value=value2
> row3
> column=cf:c, timestamp=1339581566227, value=value3
>
> Thanks again for the correct pointers…. :-)
>
> Cheers,
> Subroto Sanyal
> On Jun 14, 2012, at 9:07 AM, Sonal Goyal wrote:
>
>> Are you doing something specific with the RecordReader? Maybe you can post
>> more of your code as it is difficult to tell anything right now.
>>
>> Best Regards,
>> Sonal
>> Crux: Reporting for HBase <https://github.com/sonalgoyal/crux>
>> Nube Technologies <http://www.nubetech.co>
>>
>> <http://in.linkedin.com/in/sonalgoyal>
>>
>>
>>
>>
>>
>> On Wed, Jun 13, 2012 at 7:28 PM, Subroto <[email protected]> wrote:
>>
>>> Hi Sonal,
>>>
>>> The Scan is being created by:
>>> void
>>> org.apache.hadoop.hbase.mapreduce.TableInputFormat.setConf(Configuration
>>> configuration)
>>> I am not providing any other scan options…. :-(
>>>
>>> Cheers,
>>> Subroto Sanyal
>>>
>>> On Jun 13, 2012, at 1:30 PM, Sonal Goyal wrote:
>>>
>>>> Hi Subroto,
>>>>
>>>> How are you configuring your job? Are you providing any Scan options?
>>> Check
>>>> Chapter 7 of the ref guide at
>>>>
>>>> http://hbase.apache.org/book/mapreduce.example.html
>>>>
>>>> Best Regards,
>>>> Sonal
>>>> Crux: Reporting for HBase <https://github.com/sonalgoyal/crux>
>>>> Nube Technologies <http://www.nubetech.co>
>>>>
>>>> <http://in.linkedin.com/in/sonalgoyal>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On Wed, Jun 13, 2012 at 4:47 PM, Subroto <[email protected]> wrote:
>>>>
>>>>> Hi,
>>>>>
>>>>> I have a table with details:
>>>>> hbase(main):024:0> scan 'test'
>>>>> ROW
>>>>> COLUMN+CELL
>>>>> row1
>>>>> column=cf:a, timestamp=1339581548508, value=value1
>>>>> row2
>>>>> column=cf:b, timestamp=1339581557585, value=value2
>>>>> row3
>>>>> column=cf:c, timestamp=1339581566227, value=value3
>>>>> 3 row(s) in 0.0200 seconds
>>>>>
>>>>> When my MR job tries to access TableRecordReader
>>>>> org.apache.hadoop.hbase.client.HTable.ClientScanner.nextScanner set the
>>>>> "value" to null for every call which gives a sense to my MR application
>>>>> that there are no records in the table.
>>>>>
>>>>> I am using: 0.92.1 HBase and 0.23.1 Hadoop…..
>>>>>
>>>>> What can be the possible reason(s) behind it??
>>>>>
>>>>> Cheers,
>>>>> Subroto Sanyal
>>>
