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From "Hoss Man (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (LUCENE-7159) improve spatial point/rect vs. polygon performance
Date Mon, 09 May 2016 22:20:13 GMT

     [ https://issues.apache.org/jira/browse/LUCENE-7159?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Hoss Man updated LUCENE-7159:
-----------------------------
    Fix Version/s:     (was: 6.0)
                   master (7.0)


Manually correcting fixVersion per Step #S5 of LUCENE-7271


> improve spatial point/rect vs. polygon performance
> --------------------------------------------------
>
>                 Key: LUCENE-7159
>                 URL: https://issues.apache.org/jira/browse/LUCENE-7159
>             Project: Lucene - Core
>          Issue Type: Bug
>            Reporter: Robert Muir
>             Fix For: 6.1, master (7.0)
>
>         Attachments: LUCENE-7159.patch, LUCENE-7159.patch
>
>
> Now that we can query on complex polygons without going OOM (LUCENE-7153), we should
do something to address the current 🐢 performance.
> Currently, we use a basic crossings test ({{O\(n)}}) for boundary cases. We defer these
expensive per-doc checks on boundary cases to a two phase iterator (LUCENE-7019, LUCENE-7109),
so that it can be avoided if e.g. excluded by filters, conjunctions, deleted doc, and so on.
This is currently important for performance, but basically its shoving the problem under the
rug and hoping it goes away. At least for point in poly, there are a number of faster techniques
described here: http://erich.realtimerendering.com/ptinpoly/
> Additionally I am not sure how costly our "tree traversal" (rectangle intersection algorithms).
Maybe its nothing to be worried about, but likely it too gets bad if the thing gets complex
enough. These don't need to be perfect but need to behave like java's Shape#contains (can
conservatively return false), and Shape#intersects (can conservatively return true). Of course,
if they are too inaccurate, then things can get slower.
> In cases of precomputed structures we should also consider memory usage: e.g. we shouldn't
make a horrible tradeoff there.



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