Date: Sat, 18 May 2019 19:48:41 -0400
From: Stephen Frost <sfrost@snowman.net>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Tomas Vondra <tomas.vondra@2ndquadrant.com>,
	Andres Freund <andres@anarazel.de>,
	Dean Rasheed <dean.a.rasheed@gmail.com>,
	PostgreSQL Hackers <pgsql-hackers@postgresql.org>
Subject: Re: Multivariate MCV stats can leak data to unprivileged users
Message-ID: <20190518234841.GE6197@tamriel.snowman.net>
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Greetings,

* Tom Lane (tgl@sss.pgh.pa.us) wrote:
> Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> > On Sat, May 18, 2019 at 03:45:11PM -0400, Tom Lane wrote:
> >> Tomas Vondra <tomas.vondra@2ndquadrant.com> writes:
> >>> But that's not an issue intruduced by PG12, it works like that even f=
or
> >>> the extended statistics introduced in PG10.
>=20
> >> Yeah, but no time like the present to fix it if it's wrong ...
>=20
> > Sorry, not sure I understand. Are you saying we should try to rework
> > this before the beta1 release, or that we don't have time to do that?
>=20
> > I think we have four options - rework it before beta1, rework it after
> > beta1, rework it in PG13 and leave it as it is now.
>=20
> Yup, that's about what the options are.  I'm just voting against
> "change it in v13".  If we're going to change it, then the fewer
> major versions that have the bogus definition the better --- and
> since we're changing that catalog in v12 anyway, users will see
> fewer distinct behaviors if we do this change too.
>=20
> It's very possibly too late to get it done before beta1,
> unfortunately.  But as Andres noted, post-beta1 catversion
> bumps are hardly unusual, so I do not think "rework after
> beta1" is unacceptable.

Agreed.

Thanks,

Stephen

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