diff --git a/swh/core/db/db_utils.py b/swh/core/db/db_utils.py
--- a/swh/core/db/db_utils.py
+++ b/swh/core/db/db_utils.py
@@ -662,3 +662,12 @@
             "Asked for flavor %s, but module does not support database flavors",
             flavor,
         )
+
+    # Grant read-access to guest user on all tables of the schema
+    with connect_to_conninfo(db_or_conninfo) as db:
+        if not db:
+            return None
+
+        with db.cursor() as c:
+            query = "grant select on all tables in schema public to guest"
+            c.execute(query)