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Posted to users@jena.apache.org by Olivier Dameron <ol...@univ-rennes1.fr> on 2021/05/03 17:14:29 UTC

Re: [SOLVED] jena4: negation and filter

On 5/3/21 7:01 PM, Andy Seaborne wrote:
> https://issues.apache.org/jira/browse/JENA-1963
> 
> Try
> 
> sparql --strict
> sparql --engine=ref
> sparql --optimize=off
> 
> The optimization rule that sees "FILTER(?n = ?m)" and tries to make it a 
> join goes wrong because of the interaction with substitution.

yes, this solves the issue

> 
> BTW:
> https://afs.github.io/substitute.html
> 
> lists several problems with NOT EXISTS and gives a solution.
> 
> The solution would also work for parameterized queries if the 
> scope-renaming is omitted.

ah, thank you for the pointer!
olivier