On Mon, Jul 10, 2006 at 12:36:34PM -0400, Tom Lane wrote: > Now that the index options infrastructure is in, I am having a couple of > second thoughts about the specific behavior that's been implemented, > particularly for btree fillfactor. > > 1. ... I'm thinking > we could change the nbtsort.c code to work like "stop filling page > when fillfactor is exceeded AND there are at least two entries already". > Then any old fillfactor would work. > > 2. ... There's a case to be made for making > leaf and non-leaf fillfactors accessible as separate knobs, but I'm > inclined just to use a fixed value of 70 for non-leaf factor.... > > 3. What should the minimum fillfactor be? The patch as submitted > set the minimum to 50% for all relation types. I'm inclined to > think we should allow much lower fillfactors, maybe down to 10%. > A really low fillfactor could be a good idea in a heavily updated > table --- at least, I don't think we have any evidence to prove > that it's not sane to want a fillfactor below 50%. > > Comments? > > regards, tom lane
I would like to place my vote for supporting fillfactors less than 50%. Like you mentioned, a heavily updated table could be forced to a page split before VACUUM freed the items and made them available for reuse. I also think that points 1 and 2 are reasonable. Ken ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
