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https://issues.apache.org/jira/browse/LUCENE-6037?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14193740#comment-14193740
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zhanlijun commented on LUCENE-6037:
-----------------------------------
Lucene-spatial module changes are unrelated to the bug, because the bug
also happens when I use the native lucene-spatial module.
lucene-spatial module is widely used in mobile internet applications of
china. I have an application scenario is to calculate the distance between the
user and all POIs in the city. However, when the number of POIs in one city
more than 100000, the distance calculation of lucene becomes very slow (more
than 10ms). Lucene use spatial4j HaversineRAD to calculate the distance, and I
have do a test on my computer (2.9GHz Intel Core i7, 8GB mem)
POI num | time
5w | 7ms
10w | 14ms
100w | 144ms
I did some simplified the distance calculation formula. This
simplification greatly improve the computational efficiency under the premise
of maintaining the use of precision. Here is the result of the test.
test point pair | disSimplify(meter)
| distHaversineRAD(meter) | diff(meter)
（39.941, 116.45）（39.94, 116.451） | 140.0242769266660 |
140.02851671981400 | 0.0
（39.96 116.45）（39.94, 116.40） | 4804.113098854450 | 4804.421153907680
| 0.3
（39.96, 116.45）（39.94, 117.30） | 72438.90919479560 | 72444.54071519510
| 5.6
（39.26, 115.25）（41.04, 117.30） | 263516.676171262 | 263508.55921886700
| 8.1
POI num | time
5w | 0.1
10w | 0.3
100w | 4
> PendingTerm cannot be cast to PendingBlock
> ------------------------------------------
>
> Key: LUCENE-6037
> URL: https://issues.apache.org/jira/browse/LUCENE-6037
> Project: Lucene - Core
> Issue Type: Bug
> Components: core/codecs
> Affects Versions: 4.3.1
> Environment: ubuntu 64bit
> Reporter: zhanlijun
> Priority: Critical
> Fix For: 4.3.1
>
>
> the error as follows:
> java.lang.ClassCastException:
> org.apache.lucene.codecs.BlockTreeTermsWriter$PendingTerm cannot be cast to
> org.apache.lucene.codecs.BlockTreeTermsWriter$PendingBlock
> at
> org.apache.lucene.codecs.BlockTreeTermsWriter$TermsWriter.finish(BlockTreeTermsWriter.java:1014)
> at
> org.apache.lucene.index.FreqProxTermsWriterPerField.flush(FreqProxTermsWriterPerField.java:553)
> at
> org.apache.lucene.index.FreqProxTermsWriter.flush(FreqProxTermsWriter.java:85)
> at org.apache.lucene.index.TermsHash.flush(TermsHash.java:116)
> at org.apache.lucene.index.DocInverter.flush(DocInverter.java:53)
> at
> org.apache.lucene.index.DocFieldProcessor.flush(DocFieldProcessor.java:81)
> at
> org.apache.lucene.index.DocumentsWriterPerThread.flush(DocumentsWriterPerThread.java:493)
> at
> org.apache.lucene.index.DocumentsWriter.doFlush(DocumentsWriter.java:480)
> at
> org.apache.lucene.index.DocumentsWriter.postUpdate(DocumentsWriter.java:378)
> at
> org.apache.lucene.index.DocumentsWriter.updateDocuments(DocumentsWriter.java:413)
> at
> org.apache.lucene.index.IndexWriter.updateDocuments(IndexWriter.java:1283)
> at
> org.apache.lucene.index.IndexWriter.addDocuments(IndexWriter.java:1243)
> at
> org.apache.lucene.index.IndexWriter.addDocuments(IndexWriter.java:1228)
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