If you look at this web page you'll see that pg_contraint has a column
named confkey[]. It's an array of type int2[] that maps back to
pg_attribute.attnum to get the columns involved in the foreign key, how do
I use these array types, I need to bind back to pg_attribute and get the
list of columns, do I need to pull that data back, parse it in my
application code and hit pg_attribute with an IN clause or something?
http://www.postgresql.org/docs/7.4/static/catalog-pg-constraint.html