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https://issues.apache.org/jira/browse/JENA-1044?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14944920#comment-14944920
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ASF subversion and git services commented on JENA-1044:
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Commit 3b37942c71411347d5fb4d7891d2eacbeabad972 in jena's branch
refs/heads/master from [~andy.seaborne]
[ https://git-wip-us.apache.org/repos/asf?p=jena.git;h=3b37942 ]
JENA-1044: Avoid creating an exception on the normal execution path.
> Significant performance improvement in E_Bound
> ----------------------------------------------
>
> Key: JENA-1044
> URL: https://issues.apache.org/jira/browse/JENA-1044
> Project: Apache Jena
> Issue Type: Improvement
> Reporter: Robert Mercer
> Priority: Minor
> Attachments: PercentTime_clean.png, RuntimeException_clean.png
>
>
> I would like to suggest a significant performance improvement that I've seen
> occurring in various setups. Basically the issue occurs if you do a
> bound(?somethingthatsnotbound) this causes an "internal" runtime exception to
> be thrown down in the code which in turn is caught and handled by returning a
> false from E_Bound. This only occurs in the case of a bound(?x) returning
> false. This is an issue as runtimeexceptions are very costly and if you do
> this quite a lot in your query or attempt to do many queries that have lots
> of bound() functions in them you can end up with significant performance
> degradation.
> Suggested fix in E_Bound.java
> {noformat}
> @Override
> public NodeValue evalSpecial(Binding binding, FunctionEnv env)
> {
> if (expr instanceof NodeValue){
> return NodeValue.TRUE; // probably just our code has
> this case as we do some prebindings.
> } else {
> return binding.contains(expr.asVar()) ? NodeValue.TRUE
> : NodeValue.FALSE;
> }
> }
> {noformat}
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