Re: index-only-scan when there is an index on all columns

"David G. Johnston" <david.g.johnston@gmail.com> writes:

> Also, I recall discussion that select statements will touch the visibility
> map (hence causing write I/O even in a read-only query) but [1] indicates
> that only vacuum will set them ddl will clear them.

Hm, I don't recall that, but I've not been involved in the last few rounds
of hacking on that mechanism.