Q:

Checking timestamps in PL/pgSQL

If I have a function in PL/pgSQL that takes in a timestamp, what is the best way to identify whether that date is less than 12 months in the past?
e.g.
CREATE FUNCTION do_something(foo timestamp) ....
    -- IF foo is less than 12 months in the past THEN
    --    do something
    -- END IF;
END;

A:

Read about intervals on PostgreSQL doc: Date Types. Use something like:
where foo < CURRENT_TIMESTAMP - interval '12 months'

