From: | Jaime Casanova <systemguards(at)gmail(dot)com> |
---|---|
To: | PG Hackers <pgsql-hackers(at)postgresql(dot)org> |
Subject: | avoid pulling up subquerys that contain volatile functions? |
Date: | 2005-10-08 15:51:14 |
Message-ID: | c2d9e70e0510080851h3396e2b3hd1b21f83fe6f281c@mail.gmail.com |
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Lists: | pgsql-hackers |
the comments fot contain_volatile_functions in clauses.c says...
src/backend/optimizer/util/clauses.c:
*
* XXX we do not examine sub-selects to see if they contain uses of
* volatile functions. It's not real clear if that is correct or not...
*/
but this example seems to clarify (or at least i think) that we have to avoid
pulling up subquerys containing volatile functions:
--- BEGIN SQL ---
create view vfoo_random as
select alu_codigo, is_true
from (select alu_codigo, (random() * 5) as is_true
from rec_m_alumno) as t_tmp
where is_true > 1;
select count(*) from vfoo_random where is_true < 1;
drop view vfoo_random;
--- END SQL ---
i thought it was just calling contain_volatile_function from
is_simple_subquery() in src/backend/optimizer/prep/prepjointree.c but it doesn't
work for me.
what i miss?
--
regards,
Jaime Casanova
(DBA: DataBase Aniquilator ;)
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