GitHub user ddvlanck added a comment to the discussion: Performance issues on small dataset: any recommended configuration or tuning options?
Hi! 👋 Thanks a lot for the detailed explanation. That’s very helpful — we’ll definitely lower the heap size accordingly to leave more room for off-heap memory. As for the queries, they all follow the same general structure: ``` PREFIX xsd: <http://www.w3.org/2001/XMLSchema#> PREFIX tm: <https://movias.eu/ns/trafficMeasurements#> PREFIX time: <https://movias.eu/ns/time#> SELECT ?ts ?val FROM {{GRAPH}} WHERE { ?obs a tm:TrafficMeasurement ; tm:TrafficMeasurement.measureLocation ?measureLocationId ; tm:TrafficMeasurement.result ?val ; tm:TrafficMeasurement.featureOfInterest ?featureOfInterest ; tm:TrafficMeasurement.vehicleType ?vehicleType ; tm:TrafficMeasurement.time ?timeNode . ?timeNode time:Time.dateTime ?ts . FILTER (xsd:dateTime(?ts) >= "{{FROM}}"^^xsd:dateTime && xsd:dateTime(?ts) <= "{{TO}}"^^xsd:dateTime) FILTER (?featureOfInterest = <https://data.vlaanderen.be/id/concept/VkmVerkeersKenmerkType/aantal>) FILTER (?vehicleType = <https://data.vlaanderen.be/id/concept/VkmVoertuigType/fiets>) } ORDER BY ?ts ``` During testing, the query pattern stays the same — only the temporal range changes between runs, starting at 15 minutes and gradually expanding up to 10 years. I’ve also made a small sample dataset publicly available so you can reproduce the issue: https://github.com/ddvlanck/traffic-measurements-synthetic-data. These are some of the ranges for which the query failed: - `2020-05-28T13:47:07` - `2020-05-28T14:02:07` - `2015-05-12T02:55:38` - `2015-05-12T04:55:38` - `2020-01-02T08:21:29` - `2021-01-02T08:21:29` - `2015-01-01T00:14:35` - `2025-01-01T00:14:35` I’ll take a closer look at the TDB optimiser documentation and use qparse to inspect the optimised algebra, as you suggested GitHub link: https://github.com/apache/jena/discussions/3600#discussioncomment-15031496 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
