Tom Lane wrote: > Bruce Momjian <[EMAIL PROTECTED]> writes: > > Tom Lane wrote: > >> During btree index build, sort equal-keyed tuples according to their > >> TID (heap position). This doesn't do anything to the validity of the > >> finished index, but by pretending to qsort() that there are no really > >> equal keys in the sort, we can avoid performance problems with qsort > >> implementations that have trouble with large numbers of equal keys. > >> Patch from Manfred Koizar. > > > I think there is also the advantage that many equal keys will access the > > heap in a more sequential, rather than random, order, which is the part > > that really excited me. > > But we aren't attempting to maintain that ordering after index build. > (In fact, it was exactly that point that triggered the argument last > time round ...)
Agreed, but we don't maintain CLUSTER either. I see no harm in having it start out ordered, at least. -- 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 4: Don't 'kill -9' the postmaster
