I have two immutable Pl/PG funcs - func A takes a parameter X, looks up related value Y from a table and passes Y to func B. Now, if I do something like select A(field_x) from bigtable it will, of course call A for every single row since paramater is changing. However, it also calls func B for every row even though most (actually all) related values Y are the same! Is this by design, or flaw in optimizer? I thought immutable funcs with the same arguments are only called once within a scope of single query, and that 'select A(...)' should have counted as single query, right? This stuff is killing me... func B is small, all table lookups optimized to the hilt but still I'm taking major performance hit as it's called hundreds/thousands of times. Any ideas? Thx, Peter