This is what you need:
https://issues.apache.org/jira/browse/HBASE-3211

On Wed, Dec 22, 2010 at 4:04 PM, Leo Alekseyev <[email protected]> wrote:

> Looking at HBASE-1537, it seems that it only limits the number of
> columns (or column families?) that the scanner returns.  This is not
> useful to us; we have only one column with one column family.  One
> solution might potentially be to add a dummy column family and then
> use HBASE-1537 with a limit of 1.  We'd do it if it's the only option,
> but we'd rather not online and offline our tables (we are talking
> about many terabytes in a production cluster).
>
> Is it somehow possible to use KeyValue.getRow() or KeyValue.getKey()
> in a scanner without returning KeyValue's?  Basically, any code that
> tries to return or make copies of entire KeyValue's is incredibly
> inefficient, since (a) we only need the key and (b) sizeof(key) is
> many orders of magnitude smaller than sizeof(value).
>
> On Wed, Dec 22, 2010 at 1:53 PM, Ted Yu <[email protected]> wrote:
> > How about HBASE-1537 ?
> >
> > On Wed, Dec 22, 2010 at 1:38 PM, Leo Alekseyev <[email protected]>
> wrote:
> >
> >> I need to retrieve row keys from several big tables.  Is it possible
> >> to do so by just reading the key and truncating the value?  I see that
> >> HBASE-1481 implements FirstKeyOnlyFilter, but it doesn't help in our
> >> case, since we have only one KeyValue per row, and it stores binary
> >> data.
> >>
> >> Is there an easy way to accomplish fast key-only retrieval?
> >>
> >> --Leo
> >>
> >
>

Reply via email to