Andrew - Supernews wrote: > The problem is that even with the unnamed statement and deferred planning, > the planner still has to treat the parameters as variables, not constants, > since nothing in the protocol stops you from running multiple portals from > the unnamed statement. This can make a significant difference, especially > where function calls are involved and major optimizations can be made on > constant values as a result of inlining.
Sure, expression optimization is less aggressive, but is that on its own really going to produce a 100-fold difference in query execution? The main problem pre-8.0 (or with named statements) is that index selectivity estimates go out the window with a parameterized query, so a much more general (and slower) plan gets chosen. The 8.0 unnamed-statement behaviour glues the actual parameter values into the selectivity estimates so in theory you should get the same plan for the unparameterized and parameterized-unnamed-statement cases. This is why I'd like to see the actual query.. -O ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
