Yes, we can tell HBase API only scan rows start with a key.
// get rows start from startRow to table end
HTable.getScanner(final byte[][] columns, final byte [] startRow)

// get rows start from startRow to table end, only the cells time stamp
<= timestamp are retrieved
HTable.getScanner(final byte[][] columns, final byte [] startRow, long
timestamp)

// get row range [startRow, endRow )
HTable.getScanner(final byte [][] columns, final byte [] startRow, final
byte [] stopRow)

// get row range [startRow, endRow ), only the cells time stamp <= timestamp
are retrieved
HTable.getScanner(final byte [][] columns, final byte [] startRow, final
byte [] stopRow, final long timestamp)

Can any expert share your ideas about:
1. If the rowkey is not chronological, how can I only process the newly
added/updated rows?
2. How can I remove the old rows which are inserted three months ago?

Schubert

On Wed, Mar 4, 2009 at 3:10 AM, Slava Gorelik <[email protected]>wrote:

> Thank You for the answer.How can you tell to MR jobs which rows you want to
> get ? Is it possible to tell to MR Job give me only rows that starts with
> some key ?
>
> Best Regards.
> Slava
>
> On Tue, Mar 3, 2009 at 7:33 PM, schubert zhang <[email protected]> wrote:
>
> > In my practice, I define the 'time' as the first part of rowkey, then I
> can
> > only process the newly added rows.
> > I think my practice is not good and not appropriate for other cases,
> since
> > the rowkey definition is so important.
> > And I also want to know any good ideas.
> >
> > Another question is, how can I remove all rows which are inserted three
> > months ago?
> >
> > On Wed, Mar 4, 2009 at 12:45 AM, Slava Gorelik <[email protected]
> > >wrote:
> > - Show quoted text -
> >
> > > Hi.I have a small question about MR jobs. Is it possible to run MR job
> on
> > > part of the table ?
> > > For example I have MR job running on table and next time when run this
> > > job, I want to get only newly added or updated rows.
> > >
> > > Thank You and Best Regards.
> > >
> >
>

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