On Fri, Apr 08, 2005 at 03:15:50PM -0700, Josh Berkus wrote: > > I'm wondering if it might be useful to be able to add estimated selectivity > to > a function definition for purposes of query estimation. Currently function > scans automatically return a flat default 1000 estimated rows. It seems > like the DBA ought to be able to ALTER FUNCTION and give it a row estimate > for planning purposes.
About a month ago I mentioned that I'd find that useful. In a followup, Christopher Kings-Lynne brought up the idea of a GUC variable that could give hints about the expected row count. http://archives.postgresql.org/pgsql-hackers/2005-03/msg00146.php http://archives.postgresql.org/pgsql-hackers/2005-03/msg00153.php -- Michael Fuhr http://www.fuhr.org/~mfuhr/ ---------------------------(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
