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https://issues.apache.org/jira/browse/JENA-1785?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16989901#comment-16989901
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Pavel Mikhailovskii commented on JENA-1785:
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This is indeed a correct explanation of the problem.
To put it short, the problem is that even though newly added nodes are removed
from the local version of the not-present cache, they don't get removed from
the global cache on commit.
> A newly created node can remain invisible after commit
> ------------------------------------------------------
>
> Key: JENA-1785
> URL: https://issues.apache.org/jira/browse/JENA-1785
> Project: Apache Jena
> Issue Type: Bug
> Components: TDB2
> Affects Versions: Jena 3.13.0, Jena 3.13.1
> Reporter: Pavel Mikhailovskii
> Assignee: Andy Seaborne
> Priority: Critical
> Attachments: TestVisibilityOfChanges.java
>
> Time Spent: 1h
> Remaining Estimate: 0h
>
> A node once marked as non-present (_NodeTableCache.nonPresent_) can remain
> invisible even after it's created and the transaction is committed. That
> might happen because there's no guarantee that *all* newly created nodes will
> be eventually added to the "base" version _ThreadBufferingCache.baseCache_ of
> the _node2id_Cache_ (as the _localCache_ has limited capacity) or removed
> from the "base" version of the _nonPresent_ cache (even if they were, there
> would still be a chance of re-adding them by some read transaction).
> The simplest fix is to get rid of the _nonPresent_ cache which seems to be of
> limited use anyway. A more sophisticated fix would involve keeping track of
> all newly allocated nodes and their removal from the base version of
> _nonPresent_ cache on transaction commit.
> To reproduce: see the attached test.
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