Re: Functions and Relations

Aloha Kakuikanu wrote:
> Now returning to the main discussion. The query in question:
>
> select x,y from T
> where x=y and y=f(x)
>
> ....

More realistic example:

create table T (

    x integer,
    y integer,
);

create index Ti on T(x,y);

insert into t
select i/1000, mod(i,1000)
from Integers where i < 100000

select * from T
where x = 1 and y = x+1

Is your SQL database of choice able to find the access path where `x=1` is evaluated first, then it is joined with `y = x+1` and finally a tuple from T is fetched by index range scan? Received on Tue Nov 21 2006 - 20:17:21 CET