On Fri, 2008-07-11 at 15:25 -0600, Scott Marlowe wrote: > On Fri, Jul 11, 2008 at 3:24 PM, Simon Riggs <simon@xxxxxxxxxxxxxxx> wrote: > > > > On Fri, 2008-07-11 at 14:51 -0600, Scott Marlowe wrote: > > > >> I would kindly disagree. I'm looking at a project where HOT updates > >> are going to be a real performance enhancement, but I'll have to > >> create a hundred or so tables ALL with fillfactor tacked on the end. > > > > You clearly think that adjusting fillfactor helps in all cases with HOT. > > I disagree with that, else would have pushed earlier for exactly what > > you suggest. In fact, I've has this exact discussion previously. > > How odd, because that's clearly NOT what I said. In fact I used the > single "a" to describe the project I was looking at where having a > default table fill factor of < 100 would be very useful. OTOH, I have > stats databases that have only insert and drop child tables that would > not benefit from < 100 fill factor. For a heavily updated database, > where most of the updates will NOT be on indexed columns, as the ONE > project I'm looking at, a default fill factor would be quite a time > saver. I apologise if my phrasing sounded confrontational. For specific workloads, tuning of particular tables can be effective, I have not heard of evidence that setting fillfactor < 100 helps as an across-the-board tuning measure on longer-term tests of performance. Theoretically, it makes little sense, but current theory is not always right. Until we have even hear-say evidence of benefit, introducing a parameter would be inadvisable, IMHO. I will change that view in an instant, with reasonable evidence. -- Simon Riggs www.2ndQuadrant.com PostgreSQL Training, Services and Support
