Re: Heavy write activity on first vacuum of fresh TOAST data

[Simon Riggs <simon(at)2ndquadrant(dot)com>]

On Thu, 2007-12-13 at 15:19 -0600, Kevin Grittner wrote:
> >>> On Thu, Dec 13, 2007 at 12:12 PM, in message
> <1197569564(dot)4255(dot)1855(dot)camel(at)ebony(dot)site>, Simon Riggs <simon(at)2ndquadrant(dot)com>
> wrote: 
> > On Thu, 2007-12-13 at 11:46 -0600, Kevin Grittner wrote:
> >> If the hint bit changes are written to the WAL ...
> > 
> > They're not.
>  
> So one would expect a write-intensive initial vacuum after a
> PITR-style recovery?

Very perceptive. I was just thinking about that myself. An interesting
issue when running with full_page_writes off.
 
> What impact would lack of the hint bits have until a vacuum?

Vacuum isn't important here. Its the first idiot to read the data that
gets hit.

-- 
  Simon Riggs
  2ndQuadrant  http://www.2ndQuadrant.com