> I think the smallest fix here would be to change CheckPointPredicate() > so that if tailPage > headPage, pass headPage to SimpleLruTruncate() > instead of tailPage. Or perhaps it should go into the "The SLRU is no > longer needed" codepath in that case. If tailPage > headPage, the SLRU > isn't needed at the moment.
I spent sometime studying this and it appears to be a good approach. Passing the cutoff page as headPage (SLRU not needed code path ) instead of the tailPage to SimpleLruTruncate is already being done when the tailXid is not a valid XID. I added an additional condition to make sure that the tailPage proceeds the headPage as well. Attached is v2 of the patch. > In addition to that, we could change SerialAdd() to not zero out the > pages between old headXid and tailXid unnecessarily, but that's more of > an optimization than bug fix. Yes, I did notice that in my debugging, but will not address this in the current patch. Regards, Sami
0001-v2-Fix-false-apparent-wraparound-detected-in-pg_serial.patch
Description: 0001-v2-Fix-false-apparent-wraparound-detected-in-pg_serial.patch
