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https://issues.apache.org/jira/browse/OAK-2809?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14516558#comment-14516558
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Thomas Mueller commented on OAK-2809:
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I see this more as a workaround. It would be much better if we can solve the
problem in the DocumentNodeStore, for example run GC more often.
It is also a risk, because in some cases using an array property might actually
give us _more_ problems (for example: large list -> out of memory). If the
property is frequently updated and / or if there are many entries, the node
would become very large. Performance of adding n entries in n transactions is
O(n^2), while without the property it should be O(n\).
But I'm not against doing that. What I would do is add a simple feature flag
(system property) where this can be enabled / disabled, in case it turns out to
be a problem, and in case we want to run benchmarks with this feature enabled
against this feature disabled.
> Save Lucene directory listing as array property
> -----------------------------------------------
>
> Key: OAK-2809
> URL: https://issues.apache.org/jira/browse/OAK-2809
> Project: Jackrabbit Oak
> Issue Type: Improvement
> Components: lucene
> Reporter: Chetan Mehrotra
> Fix For: 1.3.0
>
>
> OakDirectory has to at times perform directory listing specially at the time
> of opening of index. With DocumentNodeStore such listing of child nodes
> "might" be slow if there are lots more deleted nodes and GC has not cleared
> them so far (due to OAK-1557).
> As seen in OAK-2808 Lucene might be creating and deleting lot more files. To
> speed up such lookup one OakDirectory can save the listing of child nodes as
> an array property once the writer is closed.
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