OK I know this has been long delayed but I've finished some work on the 
above.  The coster is actually doing a fairly good job.  I only recieved 
one submission from someone with data that replicated the problem, and 
was myself hard pressed to replicate the situation.  It's more-or-less a 
fencepost error.  I don't have the expertise to figure out how to make 
the coster more determinate in these types of situations.  However as 
some suggested the practice of storing actual run data from query plans 
(esp. when using precompiled and/or stored queries) would probably help 
eliminate these byt adding another weight factor (IE last time we did 
this it took X amount of time, and we estimated Y, so lets try it this 
way instead).

Unfortunately I'm a bit too pressed for time looking for a job to 
continue pursuing this research any further.

Michael Loftis


Mon, 10 Jun 2002 20:00:33 -0700
Michael Loftis <mloftis@wgops.com>
PG Index<->seqscan problems...