Re: Oracle Analytical Functions

> > I'm trying to replicate the use of Oracle's 'lag' and 'over
> > partition by' analytical functions in my query. I have a table
> > (all_client_times) such as:
> > and I would like to create a new view that takes the first table and
> > calculates the time difference in minutes between each row so that
> > the result is something like:

I thought of a another way of doing this. In my tests, it's a little
faster, too.

DROP SEQUENCE if exists seq1;
DROP SEQUENCE if exists seq2;
CREATE TEMPORARY SEQUENCE seq1 CACHE 1000;
CREATE TEMPORARY SEQUENCE seq2 CACHE 1000;

select a.client_id, b.datetime, a.datetime as previousTime, (b.datetime -
a.datetime) as difftime from
(select nextval('seq1') as s, client_id, datetime from all_client_times
order by client_id, datetime OFFSET 0) as a
inner join
(select nextval('seq2') as s, client_id, datetime from all_client_times
order by client_id, datetime OFFSET 0) as b
on a.s=(b.s-1) where a.client_id=b.client_id