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HBase, mail # user - Query a version of a column efficiently


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Re: Query a version of a column efficiently
Jerry Lam 2012-07-26, 21:40
Hi St.Ack:

Let say there are 5 versions for a column A with timestamp = [0, 1, 3, 6,
10].
I want to execute an efficient query that returns one version of the column
that has a timestamp that is equal to 5 or less. So in this case, it should
return the value of the column A with timestamp = 3.

Using the setTimeRange(5,  Long.MAX_VALUE) with setMaxVersion = 1, my guess
is that it will return the version 6 not version 3. Correct me if I'm
wrong.

Best Regards,

Jerry

On Thu, Jul 26, 2012 at 5:13 PM, Stack <[EMAIL PROTECTED]> wrote:

> On Thu, Jul 26, 2012 at 7:43 PM, Jerry Lam <[EMAIL PROTECTED]> wrote:
> > I need some advises on a problem that I'm facing using HBase. How can I
> > efficiently query a version of a column when I don't know exactly the
> > version I'm looking for?
> > For instance, I want to query a column with timestamp that is less or
> equal
> > to N, if version = N is available, return it to me. Otherwise, I want the
> > version that is closest to the version N (order by descending of
> > timestamp). That is if version = N - 1 exists, I want it to be returned.
> >
>
> Have you tried a timerange w/ minStamp of N and maxStamp of
> HConstants#LATEST_TIMESTAMP Long.MAX_VALUE) returning one version only
> (setMaxVersion(1))?
>
> St.Ack
>