On 2018-Dec-11, Jose Luis Tallon wrote: > * EXPLAIN PERFORM ALTER TABLE (EXPLAIN EXEC?) would explain + do > > ...and bonus points for explaining each step just before it is > performed. This way, It'd be easy for users to verify that a particular step > (i.e. table rewrite) is the one taking æons to run or hammering the storage.
We have a mechanism for reporting progress of DDL commands. Currently as far as I remember it's able to report VACUUM progress; there's a patch in commitfest to add support for CLUSTER. Rahila Syed in https://www.pgcon.org/2017/schedule/attachments/472_Progress%20Measurement%20PostgreSQL.pdf proposed ways to have it report for ALTER TABLE also, though I don't think anyone has worked on that. I think these two things are separate. -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
