In tracking, we have two tables that don't directly contain the partitioning key: conversion_attributes and facebook_attributions.  These tables are partitioned by iphone_application_id, but they only contain iphone_id.  I could create a function for the check constraint that looks up the iphone_application_id from the iphones parent table, but word around the block is that wouldn't be wise.

Rather than add a NOOP check constraint (1 = 1 or something), I'd rather just have none.