On Thu, Feb 2, 2012 at 12:45 PM, Robert Haas <robertmh...@gmail.com> wrote: > I believe the adequate defense that we have is precisely the logic you > are proposing to change. Regardless of whether you want to call > XMAX_INVALID a hint or, say, a giant tortoise, I am fairly sure that > we don't WAL-log setting it. That means that a bit set before a crash > won't necessarily still be set after a crash. But the corresponding > relfrozenxid advancement will be WAL-logged, leading to the problem > scenario I described.
To put that another way, the problem isn't that we might have code somewhere in the system that ignores HEAP_XMAX_INVALID. The problem is that HEAP_XMAX_INVALID might not still be set on that tuple the next time somebody looks at it, if a database crash intervenes after that bit is set and before it is flushed to disk. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
