Hi, On 2020-07-14 13:20:25 -0400, Alvaro Herrera wrote: > On 2020-Jul-13, Andres Freund wrote: > > > Hi, > > > > On 2020-07-13 17:12:18 -0400, Robert Haas wrote: > > > 1. There's nothing to identify the tuple that has the problem, and no > > > way to know how many more of them there might be. Back-patching > > > b61d161c146328ae6ba9ed937862d66e5c8b035a would help with the first > > > part of this. > > > > Not fully, I'm afraid. Afaict it doesn't currently tell you the item > > pointer offset, just the block numer, right? We probably should extend > > it to also include the offset... > > 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? > 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? Greetings, Andres Freund