Magnus Hagander <mag...@hagander.net> writes: > As Amit mentions it is also triggered by some store parameter changes. But > not all. So looking at it the other way, the part that the end user really > cares about it "which ALTER TABLE operations will rewrite the table and > which will not". Maybe what we need is a section specifically on this that > summarizes all the different ways that it can happen.
No, what we need is EXPLAIN for DDL ;-). Trying to keep such documentation in sync with the actual code behavior would be impossible. (For one thing, some aspects can be affected by extension datatype behaviors.) regards, tom lane