On 2018-05-04 11:42:35 -0700, Peter Geoghegan wrote: > On Fri, May 4, 2018 at 11:41 AM, Andres Freund <and...@anarazel.de> wrote: > > Hi, > > > > Currently there's no convenient way to get a corrupted page (be it a > > checksum failure, corrupted pd_upper/lower or whatnot) via pageinspect's > > get_raw_page(). Given that pageinspect is kind of our tool to do inspect > > issues on a data level that's not so great. > > > > I therefore propose that we add an *option* that bypasses shared buffers > > and reads the underlying data directly. And then skips over the > > validation. I'm not 100% sure if this should be done unconditionally, > > or only if the item wasn't found in cache. There's some coherency > > differences, obviously. > > +1. This would be a good option for amcheck, too.
Could you expand on that? Are you envisioning an option to ReadBufferExtended()? Because that's certainly not what I'm thinking of - it seems dangerous to populate shared buffers with an invalid page. Therefore I was more thinking to falling back to smgrread() or such. Greetings, Andres Freund
