Greg Stark <[EMAIL PROTECTED]> writes: > Tom Lane <[EMAIL PROTECTED]> writes: >> I think the one effect that's not being modeled is amortization of index >> fetches across successive queries.
> And across multiple fetches in a single query, such as with a nested loop. Right, that's effectively the same problem. You could imagine making a special-purpose solution for nestloop queries but I think the issue is more general than that. > It seems like the effective_cache_size parameter should be having some > influence here. But it doesn't :-(. e_c_s is currently only used to estimate amortization of repeated heap-page fetches within a single indexscan. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 9: the planner will ignore your desire to choose an index scan if your joining column's datatypes do not match