Vacuum freezes on certain tables and returns an error:
file seginfo for AO relation xxxx 1663/xxx/xxx (segno=1) is missing (appendonly_compaction.c:622)
Although, select/copy are being completed.
Either re-distribute or re-create the table to resolve this issue:
alter table “table_name" set with (reorganize =false) distributed randomly; alter table "table_name" set with (reorganize =true) distributed by ("distribute_key");