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https://issues.apache.org/jira/browse/JENA-1414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16256960#comment-16256960
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ASF GitHub Bot commented on JENA-1414:
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Github user afs commented on the issue:
https://github.com/apache/jena/pull/306
Revised version.
The co-iteration algorithm (choice 3) is complicated. Determining the right
thing to do each time is expensive and still a pragmatic choice with graph
probing. The app may well know what to do so call the appropriate method as
already documented.
My suggestion is algorithm 2 (a slightly improved version of the patch on
JENA-1414), document what to do if src is a large persistent database and
remove the complicate algorithm 3.
If that is our decision, I will produce a much simpler commit for algorithm
2.
> Performance regression in Model.remove(Model m) method
> ------------------------------------------------------
>
> Key: JENA-1414
> URL: https://issues.apache.org/jira/browse/JENA-1414
> Project: Apache Jena
> Issue Type: Improvement
> Components: Core
> Affects Versions: Jena 3.3.0, Jena 3.4.0
> Reporter: Michał Woźniak
> Assignee: Andy Seaborne
> Attachments: graph_util_improve.patch
>
>
> The Model.remove(Model) works very slow on large models, as it propagates to
> GraphUtil.deleteFrom(Graph, Graph), which computes size of the target graph
> by iterating over all triples. This computation takes nearly 100% of the time
> of the Model.remove(Model) operation.
> It seems this commit introduced the issue:
> https://github.com/apache/jena/commit/781895ce64e062c7f2268a78189a777c39b92844#diff-fbb4d11dc804464f94c27e33e11b18e8
> Due to this bug deletion of a concept scheme on a large ontology may take
> several minutes.
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