set zap_paths to off;
explain select * from pg_class c1, pg_class c2, pg_class c3, pg_class c4, pg_class c5 where c1.oid = c2.oid and c2.oid = c3.oid and c3.oid = c4.oid and c4.oid = c5.oid;
set zap_paths to on;
explain select * from pg_class c1, pg_class c2, pg_class c3, pg_class c4, pg_class c5 where c1.oid = c2.oid and c2.oid = c3.oid and c3.oid = c4.oid and c4.oid = c5.oid;
