Alvaro Herrera <[EMAIL PROTECTED]> writes: > Simon Riggs wrote: >> Ouch! We did discuss that also. Flushing the buffercache is nasty with >> very large caches, so this makes autovacuum much less friendly - and >> could take a seriously long time if you enforce the vacuum delay >> costings.
> Hmm, isn't the buffer cache aware of a vacuum operation? Yeah. What would probably happen is that we'd dump off most of the dirtied pages to the kernel, which would likely still have a lot of them in kernel buffers pending write. But then we'd have to fsync the table --- so a physical write storm would ensue, which we have no way to throttle. I think the don't-truncate-clog approach is a much better answer. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster