Jeff, Robert, I am still working on the "low cardinality" info you requested. Please bear with me.
In the meantime, have the following question: Are there known "scenarios" where certain types of SQL queries perform worse in PG than they do in ORacle ? For example, I have observed some discussion where MAX (In Oracle) was replaced with ORDER/DESC/LIMIT in PG. I realize this is a loaded question, but it would be great if any of you would share some observed generalities in this context. Thanks VK