OSIS-5372 enhance performance (avoiding multiple database hits to load root nodes)
OSIS-5372 enhance performance (avoiding multiple database hits to load root nodes)

uclouvain/osis,uclouvain/OSIS-Louvain,uclouvain/osis,uclouvain/osis,uclouvain/osis,uclouvain/OSIS-Louvain,uclouvain/OSIS-Louvain