Self-join of a subquery

Question

I was wondering, is it possible to join the result of a query with itself, using PostgreSQL?

Answer 1

Yes, just alias the queries:

SELECT  *
FROM    (
        SELECT  *
        FROM   table
        ) t1
JOIN    (
        SELECT  *
        FROM   table
        ) t2
ON      t1.column < t2.other_column