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Adrien Grand commented on LUCENE-9003: -------------------------------------- That works for me too. And I'd move back to the current approach on Java 8 which doesn't support the opaque memory mode? > Should FilterDirectoryReader compute numDocs lazily? > ---------------------------------------------------- > > Key: LUCENE-9003 > URL: https://issues.apache.org/jira/browse/LUCENE-9003 > Project: Lucene - Core > Issue Type: Improvement > Reporter: Adrien Grand > Priority: Minor > Time Spent: 10m > Remaining Estimate: 0h > > FilterDirectoryReader extends BaseCompositeReader, which computes both maxDoc > and numDocs eagerly in its constructor by summing up these values across all > sub leaves. > This is problematic for readers that hide additional documents. Computing > numDocs on such leaf readers usually requires iterating over all live > documents to count them. This makes creating a FilterDirectoryReader on top > run in linear time, which has caused several performance bugs to us over > time. This is especially frustrating given that numDocs is a rarely used > index statistic. > I think computing numDocs lazily would be less surprising? -- This message was sent by Atlassian Jira (v8.3.4#803005) --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@lucene.apache.org For additional commands, e-mail: issues-h...@lucene.apache.org