On 2020-Jul-14, Andres Freund wrote: > Hi, > > On 2020-07-14 13:20:25 -0400, Alvaro Herrera wrote:
> > Just having the block number is already a tremendous step forward; with > > that you can ask the customer to set a pageinspect dump of tuple > > headers, and then the problem is obvious. Now if you want to add block > > number to that, by all means do so. > > offset number I assume? Eh, yeah, that. > > One useful thing to do is to mark a tuple frozen unconditionally if it's > > marked hinted XMIN_COMMITTED; no need to consult pg_clog in that case. > > The attached (for 9.6) does that; IIRC it would have helped in a couple > > of cases. > > I think it might also have hidden corruption in at least one case where > we subsequently fixed a bug (and helped detect at least one unfixed > bug). That should only be possible if either required clog has been > removed, or if relfrozenxid/datfrozenxid are corrupt, right? Yes, that's precisely the reason I never submitted it :-) -- Álvaro Herrera https://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
