Hi,

I have started using HBase Rest Java client as a part of my project. I
see that it may have a problem with the Delete operation.
For a given Delete object, if you apply deleteColumn(family, qualifier)
on it, all matching qualifiers are deleted instead of the latest
value.

In order to recreate the problem:

1 - Create table tab1, with family fam1.
2 - Through shell, insert two values, as:
     row1, fam1, q1, val1
     row1, fam1, q1, val2
3 - Through Rest Java client:
     Delete delItem = new Delete(Bytes.toBytes("row1"));
     delItem.deleteColumn(Bytes.toBytes("fam1"), Bytes.toBytes("q1"));
     table.delete(delItem);
4 - All q1 values are deleted, instead of the latest q1 value, which is
val2.

Is that an expected result?

Thanks,
Erman

Hi Erman,

It's normal.

At t=1 you insert val1
At t=2 you insert val2
At t=3 you put a marker that row1:farm1:q1 values are deleted.

When you try to read the values, HBase will hide all that is before
t=3 because of the marker. Which mean you will not see val2 neither
you will see val1.

I think you can still see them if you read ALL the version for the row.

JM

2012/10/9, Erman Pattuk <[EMAIL PROTECTED]>:
> Hi,
>
> I have started using HBase Rest Java client as a part of my project. I
> see that it may have a problem with the Delete operation.
> For a given Delete object, if you apply deleteColumn(family, qualifier)
> on it, all matching qualifiers are deleted instead of the latest
> value.
>
> In order to recreate the problem:
>
> 1 - Create table tab1, with family fam1.
> 2 - Through shell, insert two values, as:
>      row1, fam1, q1, val1
>      row1, fam1, q1, val2
> 3 - Through Rest Java client:
>      Delete delItem = new Delete(Bytes.toBytes("row1"));
>      delItem.deleteColumn(Bytes.toBytes("fam1"), Bytes.toBytes("q1"));
>      table.delete(delItem);
> 4 - All q1 values are deleted, instead of the latest q1 value, which is
> val2.
>
> Is that an expected result?
>
> Thanks,
> Erman
>

Hi Erman:

I think this post summed up very well about deletion in hbase (
http://hadoop-hbase.blogspot.ca/2011/12/deletion-in-hbase.html) Please have
a look.

If you need to delete a specific version of a cell, you can use version
delete marker as described in the post.

Best Regards,

Jerry

On Tue, Oct 9, 2012 at 1:24 PM, Jean-Marc Spaggiari <[EMAIL PROTECTED]
> wrote:

> Hi Erman,
>
> It's normal.
>
> At t=1 you insert val1
> At t=2 you insert val2
> At t=3 you put a marker that row1:farm1:q1 values are deleted.
>
> When you try to read the values, HBase will hide all that is before
> t=3 because of the marker. Which mean you will not see val2 neither
> you will see val1.
>
> I think you can still see them if you read ALL the version for the row.
>
> JM
>
> 2012/10/9, Erman Pattuk <[EMAIL PROTECTED]>:
> > Hi,
> >
> > I have started using HBase Rest Java client as a part of my project. I
> > see that it may have a problem with the Delete operation.
> > For a given Delete object, if you apply deleteColumn(family, qualifier)
> > on it, all matching qualifiers are deleted instead of the latest
> > value.
> >
> > In order to recreate the problem:
> >
> > 1 - Create table tab1, with family fam1.
> > 2 - Through shell, insert two values, as:
> >      row1, fam1, q1, val1
> >      row1, fam1, q1, val2
> > 3 - Through Rest Java client:
> >      Delete delItem = new Delete(Bytes.toBytes("row1"));
> >      delItem.deleteColumn(Bytes.toBytes("fam1"), Bytes.toBytes("q1"));
> >      table.delete(delItem);
> > 4 - All q1 values are deleted, instead of the latest q1 value, which is
> > val2.
> >
> > Is that an expected result?
> >
> > Thanks,
> > Erman
> >
>

This link was very helpful.

Thank you all guys.

Erman
On 10/12/2012 4:45 PM, Jerry Lam wrote:
> Hi Erman:
>
> I think this post summed up very well about deletion in hbase (
> http://hadoop-hbase.blogspot.ca/2011/12/deletion-in-hbase.html) Please have
> a look.
>
> If you need to delete a specific version of a cell, you can use version
> delete marker as described in the post.
>
> Best Regards,
>
> Jerry
>
> On Tue, Oct 9, 2012 at 1:24 PM, Jean-Marc Spaggiari <[EMAIL PROTECTED]
>> wrote:
>> Hi Erman,
>>
>> It's normal.
>>
>> At t=1 you insert val1
>> At t=2 you insert val2
>> At t=3 you put a marker that row1:farm1:q1 values are deleted.
>>
>> When you try to read the values, HBase will hide all that is before
>> t=3 because of the marker. Which mean you will not see val2 neither
>> you will see val1.
>>
>> I think you can still see them if you read ALL the version for the row.
>>
>> JM
>>
>> 2012/10/9, Erman Pattuk <[EMAIL PROTECTED]>:
>>> Hi,
>>>
>>> I have started using HBase Rest Java client as a part of my project. I
>>> see that it may have a problem with the Delete operation.
>>> For a given Delete object, if you apply deleteColumn(family, qualifier)
>>> on it, all matching qualifiers are deleted instead of the latest
>>> value.
>>>
>>> In order to recreate the problem:
>>>
>>> 1 - Create table tab1, with family fam1.
>>> 2 - Through shell, insert two values, as:
>>>       row1, fam1, q1, val1
>>>       row1, fam1, q1, val2
>>> 3 - Through Rest Java client:
>>>       Delete delItem = new Delete(Bytes.toBytes("row1"));
>>>       delItem.deleteColumn(Bytes.toBytes("fam1"), Bytes.toBytes("q1"));
>>>       table.delete(delItem);
>>> 4 - All q1 values are deleted, instead of the latest q1 value, which is
>>> val2.
>>>
>>> Is that an expected result?
>>>
>>> Thanks,
>>> Erman
>>>