Re: Immutable function with bind value

Thanks Matteo for your answer...

but.. this is only a usecase... i'm currently using thing like this in
a php app,

so i'm doing kind of a as

select * from test where a = test_immutable(?);

then

execute('var');

unfortunately there, i can't to an execute(test_immutable('var'))

for now i've avoid using bind for those queries but i didn't like it....

Cheers,

Brice

On Fri, Jan 20, 2012 at 15:28, Matteo Beccati <php(at)beccati(dot)com> wrote:
> On 20/01/2012 12:43, Brice Maron wrote:
>> Hi,
>>
>> i've discovered something kind of weird  while developing my app...
>> I was trying to fetch some records in a table using a function immutable.
>> In my interface it was really slow and while i was in a psql it was
>> really fast ...
>>
>> After some research i've found out that it was caused by the bind
>> parameter "forcing" the immutable function to execute each time my
>> query gets a record.
>>
>> while i know that the value can't be known at planning time the
>> difference between the binded / not binded is quite enormous...
>>
>> i've isolated a test case here....
>>
>> https://gist.github.com/e93792540cb3a68054c9
>>
>> (it happens at least in pg 8.4 and 9.1.2)
>>
>>
>> What do you think about it... bug? feature?  how can i avoid it?
>
> How about:
>
> PREPARE test (varchar) as select * from test where a = $1;
> EXECUTE test(test_immutable(1));
>
>
> Cheers
> --
> Matteo Beccati
>
> Development & Consulting - http://www.beccati.com/