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HBase, mail # user - SingleColumnValueFilter for empty column qualifier


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Re: SingleColumnValueFilter for empty column qualifier
anil gupta 2012-11-01, 02:38
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