std::bad_alloc on simple broken query

[niklas88]

I'm trying to recreate the mediator-facts list used by Aqqu on the final freebase. Sadly my attempts provoked some QLever crashing. Before it crashes it uses a lot more RAM but it doesn't look like it quite hits out of memory. Especially since that should go to swap or awake the mighty OOM Killer.

In this query the order is wrong and thus ?s and ?o have the same function, it is NOT the correct mediator-facts query

PREFIX fb: <http://rdf.freebase.com/ns/>
SELECT DISTINCT ?s ?left ?right ?o WHERE {
    ?cvt fb:freebase.type_hints.mediator "true" .
    ?s ?left ?cvt .
    ?o ?right ?cvt .
}
LIMIT 100

[niklas88]

I've now collected a QLever log for this
qlever_crash_bad_alloc_broken_query.txt
also I now think QLever in fact just runs out of memory. The swap was was completely full and we've already seen a few OOM situations result in std::bad_alloc