Cache full

[mkyl]

I get this error when trying to run a nested OPTIONAL query:

{
    "exception": "Tried to allocate 6.6 GB, but only 3.3 GB were available. Clear the cache or allow more memory for QLever during startup",
    "query": "\nPREFIX wikibase: <http://wikiba.se/ontology#>\nPREFIX wd: <http://www.wikidata.org/entity/>\nPREFIX wdt: <http://www.wikidata.org/prop/direct/>\nPREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>\nSELECT\n  (COUNT(*) AS ?total_paths)\n  (SUM(IF(?final_node = wd:Q30, 1, 0)) AS ?target_paths)\nWHERE {\n  wd:Q191643 wdt:P1343 ?node0 .\n  OPTIONAL {\n    ?node0 wdt:P17 ?node1 .\n  OPTIONAL {\n    ?node1 wdt:P530 ?final_node .\n  }\n  }\n}",
    "resultsize": 0,
    "status": "ERROR",
    "time": {
        "computeResult": 15743,
        "total": 15743
    }
}

This is a Wikidata instance. Here is a snippet of my config file:

MEMORY_FOR_QUERIES          = 30G
CACHE_MAX_SIZE              = 20G
CACHE_MAX_SIZE_SINGLE_ENTRY = 10G
TIMEOUT                     = 600s

Any suggestions? Thank you for developing this software.