Re: Increasing Apache Jena Performance

[Andy Seaborne]

On 15/01/2026 12:24, Vince Wouters via users wrote:

Hello Jena community,

*Test Queries*
SELECT (COUNT(DISTINCT ?s) AS ?sCount) WHERE { GRAPH ?g { ?s ?p ?o } }

Takes around 80 seconds for our dataset.

SELECT (COUNT(DISTINCT CONCAT(STR(?s), STR(?p))) AS ?c) WHERE { GRAPH ?g {
?s ?p ?o } }

Takes around 120 seconds for our dataset.

Hi - would you be able to time on exactly this setup:


SELECT (COUNT(*) AS ?count) WHERE { GRAPH ?g { ?s ?p ?o } }

    Andy