Re: Proposal: Integrity check

Zdenek Kotala <Zdenek.Kotala@Sun.COM> writes:
> Tom Lane wrote:
>> This seems like a pretty horrid idea.  Bad pages shouldn't be allowed to
>> get into shared buffers in the first place.  Why not have the checking
>> logic operate outside shared buffers?

> It currently works outside the shared buffers, but I afraid about 
> collision due to parallel read and write access on one block. I'm not 
> sure if parallel write(8k) and read(8k) is synchronized by kernel/fs or 
> not. If not it should generates false positive results. If yes than I'm 
> happy :-) with outside processing.

We're already assuming that; otherwise base backups for PITR don't work.
        regards, tom lane