[
https://issues.apache.org/jira/browse/LUCENE-6477?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14552074#comment-14552074
]
Michael McCandless commented on LUCENE-6477:
--------------------------------------------
I haven't explored this yet, but talking to [~daddywri] it sounds like
integrating geo3d into the BKD tree would be quite simple, and would "solve"
the inefficiency now of visiting leaf cells outside the shape but inside its
bounding box, probably giving a good speedup over the simple polygon filtering
we do in LUCENE-6450.
> Add BKD tree for spatial shape query intersecting indexed points
> ----------------------------------------------------------------
>
> Key: LUCENE-6477
> URL: https://issues.apache.org/jira/browse/LUCENE-6477
> Project: Lucene - Core
> Issue Type: New Feature
> Reporter: Michael McCandless
> Assignee: Michael McCandless
> Fix For: Trunk, 5.2
>
> Attachments: LUCENE-6477.patch, LUCENE-6477.patch
>
>
> I'd like to explore using dedicated spatial trees for faster shape
> intersection filters than postings-based implementations.
> I implemented the tree data structure from
> https://www.cs.duke.edu/~pankaj/publications/papers/bkd-sstd.pdf
> The idea is simple: it builds a full binary tree, partitioning 2D
> space, alternately on lat and then lon, into smaller and smaller
> rectangles until a leaf has <= N (default 1024) points.
> It cannot index shapes (just points), and can then do fast shape
> intersection queries. Multi-valued fields are supported.
> I only implemented the "point is contained in this bounding box" query
> for now, but I think polygon shape querying should be easy to
> implement using the same approach from LUCENE-6450.
> For indexing, you add BKDPointField (takes lat, lon) to your doc, and
> must set up your Codec use BKDTreeDocValuesFormat for that field.
> This DV format wraps Lucene50DVFormat, but then builds the disk-based
> BKD tree structure on the side. BKDPointInBBoxQuery then requires this
> DVFormat, and casts it to gain access to the tree.
> I quantize each incoming double lat/lon to 32 bits precision (so 64
> bits per point) = ~9 milli-meter lon precision at the equator, I
> think.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
