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Accumulo, mail # user - Filtering on column qualifier


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Re: Filtering on column qualifier
John Vines 2013-08-22, 00:38
Nope, it's just a custom Filter, which is a type of iterator. You can
attach iterators to run on a scanner, you just need to make sure you deploy
the jar with the custom iterator to all of the tservers.
On Wed, Aug 21, 2013 at 7:58 PM, Slater, David M.
<[EMAIL PROTECTED]>wrote:

> Would this require extending the BatchScanner as well to make use of the
> extended ColumnQualifierFilter, or could this be done with an unmodified
> BatchScanner?****
>
> ** **
>
> *From:* John Vines [mailto:[EMAIL PROTECTED]]
> *Sent:* Wednesday, August 21, 2013 10:49 AM
> *To:* [EMAIL PROTECTED]
> *Subject:* Re: Filtering on column qualifier****
>
> ** **
>
> There's no way to extend the ColumnQualietyFilter via configuration, but
> it sounds like you are on top of it. You just need to extend the class,
> possibly copy a bit of code, and change the equality check to a compareTo
> after converting the Strings to Doubles.****
>
> ** **
>
> On Wed, Aug 21, 2013 at 10:00 AM, Marc Reichman <
> [EMAIL PROTECTED]> wrote:****
>
> I have some data stored in Accumulo with some scores stored as column
> qualifiers (there was an older thread about this). I would like to find a
> way to do thresholding when retrieving the data without retrieving it all
> and then manually filtering out items below my threshold.****
>
> ** **
>
> I know I can "fetch" column qualifiers which are exact.****
>
> ** **
>
> I've seen the ColumnQualifierFilter, which I assume is what's in play when
> I fetch qualifiers. Is there a reasonable pattern to extend this and try to
> use it as a scan iterator so I can do things like "greater than" a value
> which will be interpreted as a Double vs. the string equality going on now?
> ****
>
> ** **
>
> Thanks,****
>
> Marc****
>
> ** **
>