Re: User Defined Functions/AM's inherently slow?

On Jan 17, 2004, at 10:22 PM, Tom Lane wrote:

> Eric Ridge <ebr@tcdi.com> writes:
>> I've created a stub AM that literally does nothing.
>
> It's not possible for an index AM to "do nothing", at least not for an
> indexscan.  It has to return tuple pointers.  What are you doing for
> that?

I should have included the entire explain output:

stub AM: Index Scan using idxa_stub on test2  (cost=0.00..2.68 rows=1 width=5) 
(actual time=0.002..0.002 rows=0 loops=1)   Index Cond: (a ==> '1'::text) Total runtime: 0.247 ms

builtin btree AM:
Index Scan using idxa_btree on test2  (cost=0.00..4.68 rows=1 width=5) 
(actual time=0.024..0.026 rows=1 loops=1)   Index Cond: (a = '1'::text) Total runtime: 0.060 ms

If the "actual time" numbers are really a measure of the amount of time 
spent in (at least) the index, it seems the stub should report a 
smaller "total runtime", but alas, it doesn't.

eric