On 11/12/12 4:44 AM, Craig Ringer wrote:
> Is it absurd to suggest using another bitmap, like the FSM or visibility
> map, to store information on page checksumming while checksumming is
> enabled but incomplete?
I spent some time thinking about that last week. One problem with it is
that the bitmap structure itself has the same issues as every other
write here--how do we know it's going to disk accurately? The "put
'checksum on' bits on the page" idea and "put checksum on bits in a map"
have the same fundamental issue. Things might get out of sync in the
same way, you've just moved the potentially suspicious write to a new place.
--
Greg Smith 2ndQuadrant US greg@2ndQuadrant.com Baltimore, MD
PostgreSQL Training, Services, and 24x7 Support www.2ndQuadrant.com