In my data warehousing situation, I'd like to be able to specify that the indexes be as compact as possible (fillfactor = 100%) in order to hit as few index pages as necessary.
For summary tables there will not be any more inserts or deletions so the index will not change either. In that case, there's no point to leaving any extra room for page-splitting. At some point it would also be nice to be able to mark tables as read-only and then any indexes created on that table after that would have a fillfactor of 100%. Then I'd be able to load the table, alter it to be read-only, then add the appropriate indexes that are automatically compacted. Darren -----Original Message----- From: Bruce Momjian [mailto:[EMAIL PROTECTED] Sent: Thursday, November 04, 2004 12:19 PM To: Simon Riggs Cc: [EMAIL PROTECTED] Subject: Re: [HACKERS] Minor TODO list changes Simon Riggs wrote: > On Thu, 2004-11-04 at 16:51, Bruce Momjian wrote: > > OK, I updated all your items. > > Thanks > > > I removed fillfactor because I thought I was the only one who > > thought it was valuable and as I remember it was mostly useful for > > ISAM, which we don't support. Can you think of a use for a non-100% > > fillfactor? > > > > I was under the impression the factor was 67% for data loaded on the > leading-edge of an index, and 50% for other INSERTs. > (backend/access/nbtree/nbtinsert.c) > > Not sure, without checking, what CREATE INDEX and COPY do, but I'm > guessing it is similar? > > Other RDBMS use a higher leading-edge/standard fill factor. > > There are situations where I'd want to set it at 90%, or even 100%. If > I know the update rate is likely to be zero, then I'd like my indexes > to fit in 10-30% less memory and disk, please. > > Or am I missing something? Oh, good point. I was thinking of just the leaf pages which I think are 100% filled. -- Bruce Momjian | http://candle.pha.pa.us [EMAIL PROTECTED] | (610) 359-1001 + If your life is a hard drive, | 13 Roberts Road + Christ can be your backup. | Newtown Square, Pennsylvania 19073 ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html ---------------------------(end of broadcast)--------------------------- TIP 2: you can get off all lists at once with the unregister command (send "unregister YourEmailAddressHere" to [EMAIL PROTECTED])
