Re: Bogus collation version recording in recordMultipleDependencies

On Mon, Apr 19, 2021 at 6:45 PM Julien Rouhaud <rjuju123@gmail.com> wrote:
> > This argument seems completely absurd to me.
>
> I'm not sure why?  For glibc at least, I don't see how we could not end up
> raising false positive as you have a single glibc version for all its
> collations.  If a user has say en_US and fr_FR, or any quite stable collation,
> most of the glibc upgrades (except 2.28 of course) won't corrupt your indexes.

If the versions differ and your index happens to not be corrupt
because it just so happened to not depend on any of the rules that
have changed, then a complaint about the collation versions changing
is not what I'd call a false positive. You can call it that if you
want, I suppose -- it's just a question of semantics. But I don't
think you should conflate two very different things. You seem to be
suggesting that they're equivalent just because you can refer to both
of them using the same term.

It's obvious that you could have an absence of index corruption even
in the presence of a collation incompatibility. Especially when there
is only 1 tuple in the index, say -- obviously the core idea is to
manage the dependency on versioned collations, which isn't magic. Do
you really think that's equivalent to having incorrect version
dependencies?

-- 
Peter Geoghegan