Michael Paesold wrote: > Simon Riggs wrote: >> On Thu, 2007-10-25 at 13:41 -0300, Alvaro Herrera wrote: > ... >>> FWIW I disagree with cancelling just any autovac work automatically; in >>> my patch I'm only cancelling if it's analyze, on the grounds that if >>> you have really bad luck you can potentially lose a lot of work that >>> vacuum did. We can relax this restriction when we have cancellable >>> vacuum. >> That was requested by others, not myself, but I did agree with the >> conclusions. The other bad luck might be that you don't complete some >> critical piece of work in the available time window because an automated >> job kicked in. > > Yeah, I thought we had agreed that we must cancel all auto vacuum/analyzes, > on the ground that foreground operations are usually more important than > maintenance tasks.
What this means is that autovacuum will be starved a lot of the time, and in the end you will only vacuum the tables when you run out of time for Xid wraparound. > Remember the complaint we already had on hackers just after beta1: > auto *vacuum* blocked a schema change, and of course the user > complained. Actually I can't remember it, but I think we should decree that this is a known shortcoming; that we will fix it when we have cancellable vacuum; and that the user is free to cancel the vacuuming on his own if he so decides. -- Alvaro Herrera http://www.flickr.com/photos/alvherre/ "The ability to monopolize a planet is insignificant next to the power of the source" ---------------------------(end of broadcast)--------------------------- TIP 9: In versions below 8.0, the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
