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From "Patrone, Dennis S." <Dennis.Patr...@jhuapl.edu>
Subject RE: extension to the AgeOffFilter?
Date Tue, 24 Apr 2012 16:51:44 GMT
Great- thanks!

-----Original Message-----
From: Keith Turner [mailto:keith@deenlo.com] 
Sent: Tuesday, April 24, 2012 12:05 PM
To: dev@accumulo.apache.org
Subject: Re: extension to the AgeOffFilter?

Dennis

In 1.4 there is org.apache.accumulo.core.iterators.user.TimestampFilter

Keith

On Tue, Apr 24, 2012 at 11:31 AM, Patrone, Dennis S.
<Dennis.Patrone@jhuapl.edu> wrote:
> We have a requirement to be able to query Accumulo within a time window (start AND stop
date).  The standard AgeOffFilter allows us to get rid of the data that is too old, but we
don't have any easy way to get rid of the data that is too new.
>
> I know I can write my own filter implementation, but as I understand it, that requires
deploying a JAR across the cloud which is undesirable in our situation.
>
> We've work around the issue by creating two AgeOffFilters.  One gets rid of the data
that is too old.  The other accepts data from the current time ("now") until the time window
stop date (i.e., the data that is too new).  And then we apply negate()to that filter.
>
> It seems to me a minor change to the AgeOffFilter would allow that class to handle both
cases (age off and time windows):
>
> 1.       Provide an optional Boolean flag if the "too new" data should be ignored
as well (defaulting to false to maintain backwards compatibility).
>
> 2.       In "accept", if the flag is set and "currentTime - k.getTimestamp()" is negative
return false.
>
> Any interest in this change, or providing an alternative class (e.g., "TimeWindowFilter")?
 Or does the capability already exist somewhere and I am just missing it?
>
> Thanks,
> Dennis
>
>
> Dennis Patrone
> The Johns Hopkins University / Applied Physics Laboratory
> 240-228-2285 / Washington
> 443-778-2285 / Baltimore
> 443-220-7190 / Cell
> dennis.patrone@jhuapl.edu<mailto:dennis.patrone@jhuapl.edu>
>

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