how to get second max date in postgres sql - sql

Question

I have following situation where i need to get several values between two invoices date.
So query is giving data based on invoices now what i need to do is for some values fetch data between this invoice date and last invoice date
already tried ways
1) sub query will easily solve this but as i have to do this for 4-5 column and its a 15 gb database so that's not possible.
2) if i go like this
left join (select inv.date ,inv,actno from invoice inv) as invo on invo.actno=act.id and invo.date < inv.date
then it will give all the data less then that date but i need only one data that will be less than main invoice date.
3) we can not get second max value in subquery of from clause because outer invoice is not grouped so it might be max or midlle or least .
4) we can not send values of other table in subquery of join table.
ex
create table inv (id serial ,date timestamp without time zone);
insert into inv (date) values('2017-01-31 00:00:00'),('2017-01-30 00:00:00'),('2017-01-29 00:00:00'),('2017-01-28 00:00:00'),('2017-01-27 00:00:00');
select date as d1 from inv;
id | date
----+---------------------
1 | 2017-01-31 00:00:00
2 | 2017-01-30 00:00:00
3 | 2017-01-29 00:00:00
4 | 2017-01-28 00:00:00
5 | 2017-01-27 00:00:00
(5 rows)
I need this
id |date |date | id
1 | 2017-01-31 00:00:00 | 2017-01-30 00:00:00 | 2
2 | 2017-01-30 00:00:00 | 2017-01-29 00:00:00 | 3
3 | 2017-01-29 00:00:00 | 2017-01-28 00:00:00 | 4
4 | 2017-01-28 00:00:00 | 2017-01-27 00:00:00 | 5
5 | 2017-01-27 00:00:00 |
I can't do subquery in select as database is big and need to do this for 4-5 column
UPDATE 1
I need this from same table but using it twice in FROM clause as my requirement is that I need several data joined from invoice table and then there is 4-5 column in which I need things like sum of amount paid between last and this invoice.
So I can take both invoice date in subquery and get the data between them
UPDATE 2
lag will not solve this
select i.id,i.date, lag(date) over (order by date) from inv i order by id ;
id | date | lag
----+---------------------+---------------------
1 | 2017-01-31 00:00:00 | 2017-01-30 00:00:00
2 | 2017-01-30 00:00:00 | 2017-01-29 00:00:00
3 | 2017-01-29 00:00:00 | 2017-01-28 00:00:00
4 | 2017-01-28 00:00:00 | 2017-01-27 00:00:00
5 | 2017-01-27 00:00:00 |
(5 rows)
Time: 0.480 ms
test=# select i.id,i.date, lag(date) over (order by date) from inv i where id=2 order by id ;
id | date | lag
----+---------------------+-----
2 | 2017-01-30 00:00:00 |
(1 row)
Time: 0.525 ms
test=# select i.id,i.date, lag(date) over (order by date) from inv i where id in (2,3) order by id ;
id | date | lag
----+---------------------+---------------------
2 | 2017-01-30 00:00:00 | 2017-01-29 00:00:00
3 | 2017-01-29 00:00:00 |
it will calculate on the data it will get from the table in that query it is bounded in that query see here 3 has a lag but could not get it cause query is not allowing it to have it ....something in left join needs to be done so the lag date can be taken from same table but calling it again in from clause Thanks Again buddy

Answer 1

Like here?:
t=# select date as d1,
lag(date) over (order by date)
from inv
order by 1 desc;
d1 | lag
---------------------+---------------------
2017-01-31 00:00:00 | 2017-01-30 00:00:00
2017-01-30 00:00:00 | 2017-01-29 00:00:00
2017-01-29 00:00:00 | 2017-01-28 00:00:00
2017-01-28 00:00:00 | 2017-01-27 00:00:00
2017-01-27 00:00:00 |
(5 rows)
Time: 1.416 ms