Tom Lane wrote:
In the worst case autovac could be starved out for a long time. I don't have any immediate good idea about how to fix that, but the worst consequences could be avoided if we disable the cancellation ability when running an anti-wraparound vacuum. Further down the road (*not* 8.3), when we teach autovac about maintenance windows, it might also disregard cancels during a maintenance window.
During maintenance window, it could instead lower vacuum cost delay in the case it would otherwise abort. That would also make sure that the task would finally finish at some point (even when the maintenance window ends too early... or perhaps any cleanup task started during a maintenance window should keep it's "maintenance priority"?)
Best Regards Michael Paesold ---------------------------(end of broadcast)--------------------------- TIP 5: don't forget to increase your free space map settings