On Sat, Jul 24, 2021 at 10:01:05AM -0400, Bruce Momjian wrote: > On Fri, Jul 23, 2021 at 09:01:18PM -0400, Bruce Momjian wrote: > > On Fri, Jul 23, 2021 at 05:47:18PM -0700, Peter Geoghegan wrote: > > > > I could perhaps see corruption happening if pg_control's oldest xid > > > > value was closer to the current xid value than it should be, but I can't > > > > see how having it 2-billion away could cause harm, unless perhaps > > > > pg_upgrade itself used enough xids to cause the counter to wrap more > > > > than 2^31 away from the oldest xid recorded in pg_control. > > > > > > > > What I am basically asking is how to document this and what it fixes. > > > > > > ISTM that this is a little like commits 78db307bb2 and a61daa14. Maybe > > > take a look at those? > > > > Agreed. I just wanted to make sure I wasn't missing an important aspect > > of this patch. Thanks. > > Another question --- with the previous code, the oldest xid was always > set to a reasonable value, -2 billion less than the current xid. With > the new code, the oldest xid might be slightly higher than the current > xid if they use -x but not -u. Is that acceptable? I think we agreed it > was. pg_upgrade will always set both.
This patch has been applied back to 9.6 and will appear in the next minor release. -- Bruce Momjian <br...@momjian.us> https://momjian.us EDB https://enterprisedb.com If only the physical world exists, free will is an illusion.
