Tom Lane wrote: > Mary Edie Meredith <[EMAIL PROTECTED]> writes: > > Stephan Szabo kindly responded to our earlier queries suggesting we look > > at default_statistics_target and ALTER TABLE ALTER COLUMN SET > > STATISTICS. > > > These determine the number of bins in the histogram for a given column. > > But for a large number of rows (for example 6 million) the maximum value > > (1000) does not guarantee that ANALYZE will do a full scan of the table. > > We do not see a way to guarantee the same statistics run to run without > > forcing ANALYZE to examine every row of every table. > > Do you actually still have a problem with the plans changing when the > stats target is above 100 or so? I think the notion of "force ANALYZE > to do a full scan" is inherently wrongheaded ... it certainly would not > produce numbers that have anything to do with ordinary practice. > > If you have data statistics that are so bizarre that the planner still > gets things wrong with a target of 1000, then I'd like to know more > about why.
Has there been any progress in determining if the number of default buckets (10) is the best value? -- 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 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match
