Hi,
It’s fixed, thanks !
VACUUM FULL ANALYZE + re-indexation did the job.
We executed the following command, as postgres user, to execute it on all the tables:
for TABLE in $(psql -d sonar -c "\dt" | grep table | awk -F "|" '{print $2}' | tr -d " "); do psql -d sonar -c "VACUUM FULL ANALYZE $TABLE" ; done