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From "Patrone, Dennis S." <Dennis.Patr...@jhuapl.edu>
Subject extension to the AgeOffFilter?
Date Tue, 24 Apr 2012 15:31:55 GMT
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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