accumulo-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Slater, David M." <David.Sla...@jhuapl.edu>
Subject RE: Filtering on column qualifier
Date Wed, 21 Aug 2013 23:58:49 GMT
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:vines@apache.org]
Sent: Wednesday, August 21, 2013 10:49 AM
To: user@accumulo.apache.org
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 <mreichman@pixelforensics.com<mailto:mreichman@pixelforensics.com>>
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


Mime
View raw message