Hello, I think this demonstrates a bug, tested in 11.5: https://gist.github.com/wkalt/a298fe82c564668c803b3537561e67a0
The same script succeeds if the index on line 11 is either dropped, made to be non-partial on b, or shifted to a different column (the others are used in the partitioning; maybe significant). This seems somewhat related to https://www.postgresql.org/message-id/flat/CAFjFpRc0hqO5hc-%3DFNePygo9j8WTtOvvmysesnN8bfkp3vxHPQ%40mail.gmail.com#00ca695e6c71834622a6e42323f5558a . Regards, Wyatt
