Re: 10.1: hash index size exploding on vacuum full analyze

> Initially, I have also thought of doing it in swap_relation_files, but
> we don't have stats values there.  We might be able to pass it, but
> not sure if there is any need for same.  As far as Toast table's case
> is concerned, I don't see the problem because we are copying the data
> row-by-row only for heap where the value of num_tuples and num_pages
> could be different.  See  copy_heap_data.

Ok, agree. AP (sorry, I don't see your name), could your check that patch fixes 
your issue?

Nevertheless, I'm going to push this patch in any case and, suppose, it should 
be backpatched to version 10 too, although the bug is not about data loss or any 
corruption. But patch looks rather  straightforward and has low risk of some new 
bugs.
-- 
Teodor Sigaev                                   E-mail: teodor@sigaev.ru
                                                    WWW: http://www.sigaev.ru/