Re: Strange behaviour ( function cachable )

"Tom Lane" <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote in message
news:11105(dot)1040238975(at)sss(dot)pgh(dot)pa(dot)us(dot)(dot)(dot)
> "Gaetano Mendola" <mendola(at)bigfoot(dot)com> writes:
> > I expected that if a function is cachable and is used
> > inside a select like:
> > SELECT * FROM foo WHERE id = my_func( a_param )
> > then the function my_func is called one for each different value
> > of a_param.
>
> That is not what "cachable" means to Postgres. There is no function
> result cache such as you seem to envision.
>
> regards, tom lane

Just to understand, do you mean that the following behaviour is
correct?

# create table test( a int, b int );
CREATE

# insert into test values (1,2);
INSERT 79298997 1
# insert into test values (1,2);
INSERT 79298998 1
# insert into test values (1,2);
INSERT 79298999 1

#select * from test where a = sp_cache( 3 );
NOTICE: CALLED
a | b
---+---
(0 rows)

#select sp_test ( 4);
NOTICE: CALLED
NOTICE: CALLED
NOTICE: CALLED
sp_test
---------

(1 row)

where sp_cache is a function declared ( iscachable )
and do a notice each time that is called
and sp_test is a function that perform:
"select * from test where a = sp_cache( 3 )"

How you can see in the first case I see only a NOTICE
in the second case I see 3 NOTICE, why ? Am I wrong ?

Ciao
Gaetano