[
https://issues.apache.org/jira/browse/CALCITE-1861?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17203579#comment-17203579
]
Julian Hyde commented on CALCITE-1861:
--------------------------------------
[~jnh5y], There were a couple of problems. I couldn't find a pre-built jar for
SFCurve on Maven Central. (I see there are jars there now, but they weren't
there when I started working on this.
Second, SFCurve is written in Scala, and I wasn't sure how it would
interoperate from Java. I had already settled on {{com.google.uzaygezen}} and
was really looking for examples for how to use it, and the easiest thing was to
translate a couple of classes in SFCurve I found that used it. I kept the
copyright notice in the files, as required by the license.
Regarding overlay operations. You may notice that the focus of Calcite, as a
query optimizer, is not to use or implement geospatial algorithms as such, but
to find algebraic transformations that allow different access patterns to data.
The Hilbert curve is excellent because it converts operations into a series of
scans. We implement the full set of ST_xxx functions, but the query executes
ST_DWithin once per row on a million row table, our aim is to find ways to
execute ST_DWithin a hundred times rather than a million times.
Do you know of a repository of such rewrite techniques? We would like to bring
those rewrites to people who are general-purpose databases.
> Spatial index, based on Hilbert space-filling curve
> ---------------------------------------------------
>
> Key: CALCITE-1861
> URL: https://issues.apache.org/jira/browse/CALCITE-1861
> Project: Calcite
> Issue Type: Improvement
> Components: spatial
> Reporter: Atri Sharma
> Assignee: Julian Hyde
> Priority: Major
> Labels: pull-request-available
> Fix For: 1.26.0
>
> Time Spent: 2h 50m
> Remaining Estimate: 0h
>
> Many Calcite users, like Phoenix and Flink can benefit from support of
> Spatial indexes.
> See:
> http://revenant.ca/www/postgis/workshop/indexing.html
--
This message was sent by Atlassian Jira
(v8.3.4#803005)
