That’s would work well enough and is my next choice.

 The thought was, rows are stored in increasing order, so as long as I know 
when I walked off the edge, and flag the iterator as empty it’d be good.  I’m 
just chasing the optimal in this case, but if it doesn’t exist, oh well.

Thank you for the reference link, it’s very helpful. 

-- 
Eugene Cheipesh

From: Russ Weeks <[email protected]>
Reply: [email protected] <[email protected]>>
Date: January 9, 2015 at 6:48:47 PM
To: [email protected] <[email protected]>>
Subject:  Re: Seeking Iterator  

Hi, Eugene,

I think the conventional approach is to decompose your search area (bounding 
box?) into a set of scan ranges that introduce minimal extraneous curve 
segments, and then pass all those scan ranges into a BatchScanner. The 
excellent Accumulo Recipes site has an example[1]. Does this approach not work 
for you?

In general, your custom iterator should never try to seek to a row id different 
from the current row id, because that row could be hosted by a different tablet 
server.

-Russ

1: 
https://github.com/calrissian/accumulo-recipes/blob/master/store/geospatial-store/src/main/java/org/calrissian/accumulorecipes/geospatialstore/support/QuadTreeHelper.java#L33

On Fri, Jan 9, 2015 at 2:37 PM, Eugene Cheipesh <[email protected]> wrote:
Hello,

I am attempting to write an Iterator based on a Z-curve index to search through 
multi-dimensional data. Essentially, given a record that I have encountered 
that is in the index range not in the multi-demensional query range I have a 
way to generate the next candidate record, potentially far ahead of the current 
point.

Ideally I would be able to refine my search range with subsequent calls to 
seek(). It appears that Accumulo will create an iterator for every RFile (or 
some split other split point). The beginning of the range argument to seek will 
be the record at beginning of this split (which is good), however all instances 
of the iterator have the same, global range end (which is bad).

I need to avoid the case where I seek past the range boundary of each 
individual iterator instance and throw a NullPointerException. Is there any way 
to get enough information to achieve this?

Thank you,

-- 
Eugene Cheipesh

Reply via email to