Thanks for copying me. I didn't look closely yet, but this comment is wrong:
+ * Since these have no storage the tablespace can be updated with a simple + * metadata only operation to update the tablespace. As I see it, AMs are a strong parallel to tablespaces. The default tablespace is convenient: 1) explicitly specified tablespace; 2) tablespace of parent, partitioned table; 3) DB tablespace; 4) default_tablespace: https://www.postgresql.org/message-id/20190423222633.GA8364%40alvherre.pgsql It'd be convenient if AMs worked the same way (and a bit odd that they don't). Note that in v15, pg_dump/restore now allow --no-table-am, an exact parallel to --no-tablespace. -- Justin