On 9 December 2014 at 06:28, Jim Nasby <jim.na...@bluetreble.com> wrote: > On 12/7/14, 6:16 PM, Simon Riggs wrote:
>> What I'm more interested in is what you plan to do with the >> information once we get it? >> >> The assumption that skipping blocks is something bad is strange. I >> added it because VACUUM could and did regularly hang on busy tables, >> which resulted in bloat because other blocks that needed cleaning >> didn't get any attention. >> >> Which is better, spend time obsessively trying to vacuum particular >> blocks, or to spend the time on other blocks that are in need of >> cleaning and are available to be cleaned? >> >> Which is better, have autovacuum or system wide vacuum progress on to >> other tables that need cleaning, or spend lots of effort retrying? >> >> How do we know what is the best next action? >> >> I'd really want to see some analysis of those things before we spend >> even more cycles on this. > > > That's the entire point of logging this information. There is an underlying > assumption that we won't actually skip many pages, but there's no data to > back that up, nor is there currently any way to get that data. There is no such underlying assumption. You assumed there was one, but there isn't one. All I can say for certain is that waiting on a lock for long periods was literally a waste of time. Now it no longer wastes time, it gets on with vacuuming the pages it can. -- 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
