Yes, I think there are these TODO items. I was waiting to see what additional replies there are before adding them. --------------------------------------------------------------------------- Matthew O'Connor wrote: > Alvaro Herrera wrote: > > Csaba Nagy wrote: > >>> Alternatively, perhaps a threshold so that a table is only considered > >>> for vacuum if: > >>> (table-size * overall-activity-in-last-hour) < threshold > >>> Ideally you'd define your units appropriately so that you could just > >>> define threshold in postgresql.conf as 30% (of peak activity in last 100 > >>> hours say). > >> No, this is definitely not enough. The problem scenario is when > >> autovacuum starts vacuuming a huge table and that keeps it busy 10 hours > >> and in the meantime the small but frequently updated tables get awfully > >> bloated... > >> > >> The only solution to that is to have multiple vacuums running in > >> parallel, and it would be really nice if those multiple vacuums would be > >> coordinated by autovacuum too... > > > > Yes, I agree, having multiple "autovacuum workers" would be useful. > > Bruce, I think there are a couple of items here that might be worth > adding to the TODO list. > > 1) Allow multiple "autovacuum workers": Currently Autovacuum is only > capable of ordering one vacuum command at a time, for most work loads > this is sufficient but falls down when a hot (very actively updated > table) goes unvacuumed for a long period of time because a large table > is currently being worked on. > > 2) Once we can have multiple autovacuum workers: Create the concept of > hot tables that require more attention and should never be ignored for > more that X minutes, perhaps have one "autovacuum worker" per hot table? > (What do people think of this?) > > 3) Create "Maintenance Windows" for autovacuum: Currently autovacuum > makes all of it's decisions based on a single per-table threshold value, > maintenance windows would allow the setting of a per-window, per-table > threshold. This makes it possible to, for example, forbid (or strongly > discourage) autovacuum from doing maintenance work during normal > business hours either for the entire system or for specific tables. > > None of those three items are on the todo list, however I think there is > general consensus that they (at least 1 & 3) are good ideas. > > > ---------------------------(end of broadcast)--------------------------- > TIP 4: Have you searched our list archives? > > http://archives.postgresql.org/ -- Bruce Momjian bruce@xxxxxxxxxx EnterpriseDB http://www.enterprisedb.com + If your life is a hard drive, Christ can be your backup. +
