I recently attended a excellent meetup about Redshift and one of the comments by the presenter was the trouble of the running of the UNLOAD command. The trouble they were having was that the UNLOAD command takes an SQL statement as a parameter, but if that SQL statement has strings, you need to escape everything which makes it fairly unreadable.
We can see an example of this in PostgreSQL using the dblink extension:
SELECT * FROM dblink('dbname=postgres', 'SELECT * FROM test WHERE b = ''2014-02-02''') AS t(a int, b date);
Since Redshift is a derivative of PostgreSQL, the dollar quoting syntax also works. Dollar quoting is a non-standard way of denoting string constants, but it makes things much simpler to read.
SELECT * FROM dblink('dbname=postgres', $$ SELECT * FROM test WHERE b = '2014-02-02' $$) AS t(a int, b date);