[The function array_position is not supported for PostgreSQL 9.](https://www.postgresql.org/docs/current/functions-array.html) Related [PR](https://github.com/OPEN-ENT-NG/support/commit/20b64e9d2234b4a9005d6908265fb5bf0b9421e2) Related ticket [CO-1796](https://jira.support-ent.fr/browse/CO-1793)
