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https://issues.apache.org/jira/browse/LUCENE-7147?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15216218#comment-15216218
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Ryan Ernst edited comment on LUCENE-7147 at 3/29/16 6:05 PM:
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I've attached 2 examples. They both use the same geo distance query. Imagine
someone from London says "I want to find places to travel within 1170km". So
they do a distance search. The [first
example|^example-intersects-bbox-not-circle.html] shows how this would require
us to compute the distances from london to all the points indexes in the box
covering Italy. The [second example|^example-crosses-axis-not-center.html]
shows how if we were to use the naive approach of using the latitude of the
circle center, we would incorrectly exclude a chunk of Poland thinking it did
not intersect the circle because all corners are outside the circle, and it
lies completely above the circle center latitude, but in fact it crosses the
axis of the bbox.
was (Author: rjernst):
I've attached 2 examples.They both use the same geo distance query. Imagine
someone from London says "I want to find places to travel within 1143km". So
they do a distance search. The "intersects bbox not circle" example shows how
this would require us to compute the distances from london to all the points
indexes in the box covering Italy. The second example shows how if we were to
use the naive approach of using the latitude of the circle center, we would
incorrectly exclude a chunk of Poland thinking it did not intersect the circle
because all corners are outside the circle, and it lies completely above the
circle center latitude, but in fact it crosses the axis of the bbox.
> Improve disjoint check for geo distance query traversal
> -------------------------------------------------------
>
> Key: LUCENE-7147
> URL: https://issues.apache.org/jira/browse/LUCENE-7147
> Project: Lucene - Core
> Issue Type: Improvement
> Reporter: Ryan Ernst
> Attachments: LUCENE-7147.patch, example-crosses-axis-not-center.html,
> example-intersects-bbox-not-circle.html
>
>
> When doing geo distance queries, it is important to avoid traversing subtrees
> which do not contain any relevant points. We currently have checks which
> compare the bbox of the query to the bounds of the subtree. However, it is
> possible for a subtree to overlap the bbox, but still not intersect the
> query. This issue is to improve that check to avoid unnecessary traversals.
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