Re: Slow case statement evaluation comparing values from two tables

Just to mention it: very good way to put the question!

If everybody would do it like this, providing answers would be a whole lot easier.

In case you want to improve this even further, please provide a working example next time.

Something like this:

create column table customers (id integer, name varchar(30))

insert into customers values (1, 'BLA');

insert into customers values (2, NULL);

insert into customers values (3, 'BLUPP');

insert into customers values (4, NULL);

insert into customers values (5, 'BLIP');

insert into customers values (6, 'BLOP');

select c1.id, c1.name as c1name, c2.name as c2name, coalesce (c1.name, c2.name)

from

    customers c1 inner join customers c2

                 on c1.id = c2.id+1

order by c1.id                

is already sufficient to work with your issue.

- Lars