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HBase, mail # user - SingleColumnValueFilter for empty column qualifier


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Re: SingleColumnValueFilter for empty column qualifier
Anoop John 2012-11-01, 06:38
You have one CF such that all rows will have KVs for that CF?
You need to implement your own filter.
Your scan can select the above CF and the on which u need the filtering.
Have a look at the QualifierFilter.. similar approach you might need to do
in the new filter..  Good luck :)

-Anoop-

On Thu, Nov 1, 2012 at 8:08 AM, anil gupta <[EMAIL PROTECTED]> wrote:

> Hi Jonathan,
>
> Then in that case SingleColumnValueFilter will not work.
> SingleColumnValueFilter works on the value of a cell rather than
> ColumnQualifier name.
> I have never heard of a built-in filter in HBase which can give you are all
> rows  where a certain column family does not have any column qualifier.
>
> You can have a look at QualifierFilter:
>
> http://hbase.apache.org/apidocs/org/apache/hadoop/hbase/filter/QualifierFilter.html
> .
> If QualifierFilter does suffices then you might have to implement by your
> own.
>
> HTH,
> Anil
>
> On Wed, Oct 31, 2012 at 4:07 PM, Jonathan Bishop <[EMAIL PROTECTED]
> >wrote:
>
> > When I created the table I created column families, one of which is say
> > "xyz".
> >
> > Now I would like to find all rows for which "xyz" is empty - in other
> words
> > no puts were made to that column family for that row.
> >
> > My column qualifiers are all "".
> >
> >
> > On Wed, Oct 31, 2012 at 3:22 PM, anil gupta <[EMAIL PROTECTED]>
> wrote:
> >
> > > Hi Jonathan,
> > >
> > > Do you mean that cell value is ""? or column qualifier is ""? I am
> > confused
> > > by your description.
> > > If you were talking about cell value, at the time of put which object
> do
> > > you use for cell value? String?
> > >
> > > Thanks,
> > > Anil
> > >
> > > On Wed, Oct 31, 2012 at 2:49 PM, Jonathan Bishop <
> [EMAIL PROTECTED]
> > > >wrote:
> > >
> > > > Hi,
> > > >
> > > > I am trying to use SingleColumnValueFilter to find only those rows
> > which
> > > > have a particular column which is empty. Not sure what to use for the
> > > value
> > > > (4th arg in const). It does not take null, and I tried something
> > like...
> > > >
> > > > byte[] v = new byte[0];
> > > >
> > > > but that does not seem to work.
> > > >
> > > > Thanks,
> > > >
> > > > Jon
> > > >
> > >
> > >
> > >
> > > --
> > > Thanks & Regards,
> > > Anil Gupta
> > >
> >
>
>
>
> --
> Thanks & Regards,
> Anil Gupta
>