Re: 16-bit page checksums for 9.2

On Friday, January 06, 2012 08:45:45 PM Heikki Linnakangas wrote:
> On 06.01.2012 20:26, Simon Riggs wrote:
> > The following patch (v4) introduces a new WAL record type that writes
> > backup blocks for the first hint on a block in any checkpoint that has
> > not previously been changed. IMHO this fixes the torn page problem
> > correctly, though at some additional loss of performance but not the
> > total catastrophe some people had imagined. Specifically we don't need
> > to log anywhere near 100% of hint bit settings, much more like 20-30%
> > (estimated not measured).
> 
> How's that going to work during recovery? Like in hot standby.
How's recovery a problem? Unless I miss something that doesn't actually 
introduce a new possibility to transport hint bits to the standby (think 
fpw's). A new transport will obviously increase traffic but ...

Andres