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From Edward Capriolo <edlinuxg...@gmail.com>
Subject Re: How can I just scan the row key ?
Date Wed, 09 Dec 2009 15:44:13 GMT
On Wed, Dec 9, 2009 at 9:45 AM, Jeff Zhang <zjffdu@gmail.com> wrote:
> Peter,
>
> Your method will scan one column family, but I just want to only scan the
> row keys. Is it possible ?
>
>
> Jeff Zhang
>
>
> On Wed, Dec 9, 2009 at 6:42 AM, Peter Rietzler <
> peter.rietzler@smarter-ecommerce.com> wrote:
>
>>
>> Sorry - I misunderstood your question. I thought that you wanted to fetch
>> only one column.
>> We fetch a reference column for our scans (which is very small):
>>
>> Scan scan = new Scan();
>> scan.addColumn("family".getBytes(), "column".getBytes());
>> table.getScanner(scan);
>>
>> Peter
>>
>>
>> Jeff Zhang-4 wrote:
>> >
>> > Peter,
>> >
>> > the api docs shows that there's no way to only get row key. So I'd like
>> to
>> > know is it make sense to provide such a API
>> >
>> >
>> > Jeff Zhang
>> >
>> >
>> > On Wed, Dec 9, 2009 at 1:48 PM, Peter Rietzler <
>> > peter.rietzler@smarter-ecommerce.com> wrote:
>> >
>> >>
>> >>
>> >> Just have a Look at the Api Docs:
>> >>
>> >>
>> http://hadoop.apache.org/hbase/docs/current/api/org/apache/hadoop/hbase/client/Scan.html
>> >>
>> >>
>> >> Jeff Zhang-4 wrote:
>> >> >
>> >> > HI all,
>> >> >
>> >> > I create a new ResultScanner like this ;
>> >> > ResultScanner scanner=table.getScanner(new Scan());
>> >> > So the default scan will scan all the families. But now I just want
to
>> >> > only
>> >> > retrieval the row keys, so is there any API for this purpose ?
>> >> >
>> >> >
>> >> > Thank you
>> >> >
>> >> >
>> >>
>> >> --
>> >> View this message in context:
>> >>
>> http://old.nabble.com/How-can-I-just-scan-the-row-key---tp26689858p26705497.html
>> >> Sent from the HBase User mailing list archive at Nabble.com.
>> >>
>> >>
>> >
>> >
>>
>> --
>> View this message in context:
>> http://old.nabble.com/How-can-I-just-scan-the-row-key---tp26689858p26711310.html
>> Sent from the HBase User mailing list archive at Nabble.com.
>>
>>
>

I pretty much just asked the same question.

Stack told me...

stack
 to hbase-user
	
show details 11:43 PM (10 hours ago)
	
Try using this filter instead:

     scan.setFilter(FirstKeyOnlyFilter.new())

Will only return row keys, if thats the effect you are looking for.

St.Ack

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