Hello, Given a table: create table atable ( item integer; ); and a view: create view aview as select item, very_expensive_function(item) as exp, cheap_function(item) as cheap from atable; Now the query: select item from aview where exp > 0 and cheap > 0; will lead to a sequential scan on atable with filter: very_expensive_function(item) > 0 and cheap_function(item) > 0 The query would run much faster with the filter reordered. Is there a way to tell the planner/optimizer that certain functions are more expensive than others, and should be postponed in lazy evaluation ? Or is there a hook in the system that would allow me too look at and maybe reorder expressions before they are executed ? Cheers, Han Holl
