Robert Haas wrote: > Regarding 0003, I'm still very much not convinced that it's a good > idea to apply this to 9.3 and 9.4. This patch changes the way we do > truncation in those older releases; instead of happening at a > restartpoint, it happens when oldestMultiXid advances. I admit that I > don't see a specific way that that can go wrong, but there are so many > different old versions with slightly different multixact truncation > behaviors that it seems very hard to be sure that we're not going to > make things worse rather than better by introducing yet another > approach to the problem. I realize that you disagree and will > probably commit this to those branches anyway. But I want it to be > clear that I don't endorse that.
Noted. I am not sure about changing things so invasively either TBH. The interactions of this stuff with other parts of the system are very complicated and it's easy to make a mistake that goes unnoticed until some weird scenario is run elsewhere. (Who would have thought that things would fail when a basebackup takes 12 hours to take and you have a custom preemptive tuple freeze script in crontab). > I wish more people were paying attention to these patches. These are > critical data-corrupting bugs, the code in question is very tricky, > it's been majorly revised multiple times, and we're revising it again. > And nobody except me and Andres is looking at this, and I'm definitely > not smart enough to get this all right. I'm also looking, and yes it's tricky. > Other issues: It would be good to pgindent the code before producing back-branch patches. I think some comments will get changed. -- Álvaro Herrera http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services -- Sent via pgsql-hackers mailing list (firstname.lastname@example.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers