On Thu, 13 Dec 2007, Simon Riggs wrote: > On Thu, 2007-12-13 at 09:46 -0600, Kevin Grittner wrote: > > Even though there have been no rollbacks, updates, or deletes on this > > table, the vacuum is writing as much as it is reading while dealing > > with the TOAST data. > > Writing hint bits. Annoying isn't it? :-( Interesting thread. Now, I know absolutely nothing about how the data is stored, but it strikes me as being non-optimal that every single block on the disc needs to be written again just to update some hint bits. Could those bits be taken out into a separate bitmap stored somewhere else? That would mean the (relatively small) amount of data being written could be written in a small sequential write to the disc, rather than very sparsely over the whole table. Matthew -- If you let your happiness depend upon how somebody else feels about you, now you have to control how somebody else feels about you. -- Abraham Hicks ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend
