Mailing-List: contact user-help@hbase.apache.org; run by ezmlm
Precedence: bulk
Reply-To: user@hbase.apache.org
Received-SPF: pass (athena.apache.org: domain of yuzhihong@gmail.com
 designates 209.85.192.181 as permitted sender)
MIME-Version: 1.0
In-Reply-To: 
 <CADoiZqq+xBh=j1-g05CNCtuLuDgGR7b54RU-1KCx-pc1MgTkFg@mail.gmail.com>
References: 
 <CADoiZqq+xBh=j1-g05CNCtuLuDgGR7b54RU-1KCx-pc1MgTkFg@mail.gmail.com>
Date: Sat, 7 Dec 2013 05:49:12 +0800
Message-ID: 
 <CALte62y4=VeW5Ctk6g=z+zH-9D-9QT2sndm18g-PgZsXp+gP_g@mail.gmail.com>
Subject: Re: HBase returns old values even with max versions = 1
From: Ted Yu <yuzhihong@gmail.com>
To: "user@hbase.apache.org" <user@hbase.apache.org>
Content-Type: multipart/alternative; boundary=bcaec520e60be97b7804ece49d9a

--bcaec520e60be97b7804ece49d9a
Content-Type: text/plain; charset=ISO-8859-1

Before the second get command was executed, was there compaction on server
side ?

You can find out by going to region server hosting row 'r1' and check
server log.

Cheers


On Sat, Dec 7, 2013 at 12:05 AM, Niels Basjes <Niels@basjes.nl> wrote:

> Hi,
>
> I have the desire to find the columns that have not been updated for more
> than a specific time period.
>
> So I want to do a scan against the columns with a timerange.
> The normal behavior of HBase is that you then get the latest value in that
> time range (which is not what I want).
>
> As far as I understand the way HBase should work is that if you set the
> maximum number of versions for the values in a column family to '1' it
> should retain only the last value that was put into the cell.
>
> What I found is different.
>
> If I do the following commands into the hbase shell
>
>     create 't1', {NAME => 'c1', VERSIONS => 1}
>     put 't1', 'r1', 'c1', 'One', 1000
>     put 't1', 'r1', 'c1', 'Two', 2000
>     put 't1', 'r1', 'c1', 'Three', 3000
>     get 't1', 'r1'
>     get 't1', 'r1' , {TIMERANGE => [0,1500]}
>
> the result is this:
>
>     get 't1', 'r1'
>     COLUMN                     CELL
>      c1:                       timestamp=3000, value=Three
>     1 row(s) in 0.0780 seconds
>
>     get 't1', 'r1' , {TIMERANGE => [0,1500]}
>     COLUMN                     CELL
>      c1:                       timestamp=1000, value=One
>     1 row(s) in 0.1390 seconds
>
> Why does the second query return a value even though I've set the max
> versions to only 1?
> I expect that it only 'knows' about the latest value ('Three') and thus
> should return an empty result in the above example.
> What is the correct way to obtain what I'm looking for?
>
> My current workaround is that I simply retrieve the latest value for all my
> columns and filter them in my application code.
>
> The HBase version I currently have installed here is HBase 0.94.6-cdh4.4.0
>
> --
> Best regards / Met vriendelijke groeten,
>
> Niels Basjes
>

--bcaec520e60be97b7804ece49d9a--