Two rows in two columns

I have table:

Owner	Book	Date
John	Vile Bodies by Evelyn Waugh	2009-05-20
Tom	Vile Bodies by Evelyn Waugh	2009-05-22
Jim	Moab is my Washpot by Stephen Fry	2009-05-26
Kate	Moab is my Washpot by Stephen Fry	2009-06-02

How can I get table:

Owner	Book	Pick_Date	Gave_Back_Book_Date
John	Vile Bodies by Evelyn Waugh	2009-05-20	2009-05-22
Tom	Vile Bodies by Evelyn Waugh	2009-05-22
Jim	Moab is my Washpot by Stephen Fry	2009-05-26	2009-06-02
Kate	Moab is my Washpot by Stephen Fry	2009-06-02

Answer

It seems you are looking for the lead() window function which allows you to access columns from the “next” row(s)

select owner, book, "date" as pick_date, 
       lead(date) over (partition by book order by "date") as return_date
from the_table
order by book, "date"

Talking about the “next” row only makes sense if the rows are sorted, that’s why the order by "date" is needed in the definition of the window