Re: a fast bloat measurement tool (was Re: Measuring relation free space)

On 2014-09-25 14:43:14 +0100, Simon Riggs wrote:
> On 25 September 2014 10:41, Andres Freund <andres@2ndquadrant.com> wrote:
> > On 2014-09-25 10:24:39 +0530, Abhijit Menon-Sen wrote:
> >> At 2014-09-24 11:09:24 +0200, andres@2ndquadrant.com wrote:
> >> > I think it's completely unacceptable to copy a visibility routine.
> >>
> >> OK. Which visibility routine should I use, and should I try to create a
> >> variant that doesn't set hint bits?
> >
> > I've not yet followed your premise that you actually need one that
> > doesn't set hint bits...
> 
> Not least because I'm trying to solve a similar problem on another
> thread, so no need to make a special case here.

That's mostly unrelated though - Abhijit wants to avoid them because he
tried to avoid having *any* form of lock on the buffer. That's the
reason he tried avoid hint bit setting. Since I don't believe that's
safe (at least there's by far not enough evidence about it), there's
simply no reason to avoid it.

Greetings,

Andres Freund

-- Andres Freund                       http://www.2ndQuadrant.com/PostgreSQL Development, 24x7 Support, Training &
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