Re: Improving RLS qual pushdown

Robert Haas wrote:
> On Wed, Jan 14, 2015 at 9:22 AM, Dean Rasheed <dean.a.rasheed@gmail.com> wrote:
> > On 14 January 2015 at 13:29, Robert Haas <robertmhaas@gmail.com> wrote:
> >> One thing they could still leak is the number of times they got
> >> called, and thus possibly the number of unseen rows.  Now if the
> >> expressions get constant-folded away that won't be an issue, but a
> >> clever user can probably avoid that.
> >
> > Right now, EXPLAIN ANALYSE can be used to tell you the number of
> > unseen rows. Is that something that people are concerned about, and
> > are there any plans to change it?
> 
> Interesting question.  I don't know.

Wasn't this part of the "covert channel" discussion that took place way
before RLS was committed?  As I recall, it was argued that such covert
channels are acceptable as long as their bandwidth is low.

-- 
Álvaro Herrera                http://www.2ndQuadrant.com/
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