Robert Haas - Thursday, March 10, 2016 No More Full-Table Vacuums
авторInstead of whole-table vacuums, we now have aggressive vacuums, which will read every page in the table that isn't already known to be entirely frozen. If you have a large database which is mostly static but which has a comparatively small active portion, this change will massively reduce the impact of wraparound vacuuming. Users with multi-terabyte databases having non-trivial write activity will be especially happy about this change. An aggressive vacuum still figures to read more data than a regular vacuum, possibly a lot more. But at least it won't read the data that hasn't been touched since the last aggressive vacuum, and that's a big improvement.