Aklakan opened a new issue, #1688: URL: https://github.com/apache/jena/issues/1688
### Version 4.7.0-SNAPSHOT ### What happened? Credits once again to @LorenzBuehmann for spotting this. The second execution of a query making use of caching such as below may return an incomplete result set. The reason is due to a bug in `QueryIterServiceBulk`: If a cache lookup detects that an empty result set has to be served then the returned empty iterator is not properly registered in the overall result iterator. ```sparql PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> SELECT * { { SELECT * { ?s a rdfs:Resource } ORDER BY ?s } # Evaluation of this following pattern on the example data occasionally # creates cache entries with empty result sets SERVICE <loop:cache:bulk+20> { ?s rdfs:label ?l } } ``` Example data: ``` PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#> <urn:example:aa> a rdfs:Resource ; rdfs:label "aa" . <urn:example:ab> a rdfs:Resource . <urn:example:ac> a rdfs:Resource . <urn:example:ad> a rdfs:Resource ; rdfs:label "ad" . ``` ### Relevant output and stacktrace _No response_ ### Are you interested in making a pull request? Maybe -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
