On 11 December 2013 17:57, Robert Haas <robertmh...@gmail.com> wrote:
> Extensive testing will be needed to prove > that the new algorithm doesn't perform worse than the current > algorithm in any important cases. Agreed, but the amount of testing seems equivalent in both cases, assuming we weren't going to skip it for this patch. Let me repeat the question, so we are clear... In what circumstances will the memory usage from multiple concurrent VACUUMs become a problem? In those circumstances, reducing autovacuum_work_mem will cause more passes through indexes, dirtying more pages and elongating the problem workload. I agree that multiple concurrent VACUUMs could be a problem but this doesn't solve that, it just makes things worse. The *only* time this parameter would have any effect looks like when it will make matters worse. With considerable regret, I don't see how this solves the problem at hand. We can and should do better. -- Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Training & Services -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
