Hi.

create table device(id int);

insert into device values(1);
insert into device values(2);
.....
insert into device values(250);

create table base (
                                        id int,
                                        data float,
                                        datatime timestamp,
                                        mode int,
                                        status int);

create table base_1 (
                                check ( id = 1 and datatime >= DATE 
'2005-01-01' 
                                        and datatime < DATE '2006-01-01' )
                                        ) INHERITS (base);

create table base_2 (
                    check ( id = 2 and datatime >= DATE '2005-01-01'
                    and datatime < DATE '2006-01-01' )
                    ) INHERITS (base);
....
create table base_250


And
select * from base 
        where id in (1,2) and datatime between '2005-05-15' and '2005-05-17';
10 seconds

select * from base
        where id in (select id from device where id = 1 or id = 2) and
        datatime between '2005-05-15' and '2005-05-17';
10 minits

Why?

-- 
mailto: [EMAIL PROTECTED]

---------------------------(end of broadcast)---------------------------
TIP 2: Don't 'kill -9' the postmaster

Reply via email to