jerakeen pointed me to a post showing how you could Generate Simple
Bar Charts From a MySQL Prompt. It's a neat trick for quickly getting
a feel for the distribution of values in a database. The post is MySQL
centric, but you can do the same thing in any database. PostgreSQL's
REPEAT
is very particular about being passed an INT, however, so you
may have to cast the second argument:
SELECT foo_id, REPEAT('#', COUNT(*)::INT) FROM bar GROUP BY 1;