2008/11/19 DANIEL CRISTIAN CRUZ <[EMAIL PROTECTED]>
> Something weird with your example which doesn't have the same result, see
> row count with explain analyze:
>
My fault. EXCEPT ALL would not work here, so this method with EXCEPT can be
used only when either operation is done on unique key on t
On Wed, 19 Nov 2008, [ISO-8859-5] ??? wrote:
> Query 1:
> select * from t1 where id not in (select id from t2);
>
> Query 2 (gives same result as Q1):
> select * from t1 except all (select id from t2);
It gives the same result as long as no nulls are in either table. If
either table
2008/11/19 Stephan Szabo <[EMAIL PROTECTED]>
>
> On Wed, 19 Nov 2008, [ISO-8859-5] Віталій Тимчишин wrote:
>
> > Query 1:
> > select * from t1 where id not in (select id from t2);
> >
> > Query 2 (gives same result as Q1):
> > select * from t1 except all (select id from t2);
>
> It gives the same
Віталій Тимчишин escribió:
> So the question is: I am willing to participate in postgresql development
> because it may be easier to fix planner then to rewrite all my queries :).
> How can I? (I mean to work on query planner enhancements by providing new
> options of query rewrite, not to work on
Something weird with your example which doesn't have the same result, see
row count with explain analyze:
cruz=# SELECT version();
version
-
Hello.
It's second query rewrite postgresql seems not to handle - making EXCEPT
from NOT IT.
Here is an example:
Preparation:
drop table if exists t1;
drop table if exists t2;
create temporary table t1(id) as
select
(random()*10)::int from generate_series(1,20) a(id);
create temporary ta
