Re: Heavy write activity on first vacuum of fresh TOAST data - Mailing list pgsql-performance

On Thu, 2007-12-13 at 15:19 -0600, Kevin Grittner wrote:
> >>> On Thu, Dec 13, 2007 at 12:12 PM, in message
> <1197569564.4255.1855.camel@ebony.site>, Simon Riggs <simon@2ndquadrant.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