It appears that the acl functions use more SELECTs than necessary. For f_customer_acl(uid integer, cid integer), I might use:

PERFORM 1 FROM customers JOIN users USING (org_id) WHERE customer_id = cid and user_id = uid;
RETURN FOUND;

This still requires one call to f_customer_acl() (and therefore one SELECT) for each row in plan_events (since that's the way the calling function is written). If the goal is to count the number of plan_events a specific user has access rights to, I'm sure you can write a query that would accomplish that directly. It's beyond my knowledge whether it makes more sense to do this via these function calls.

--Lee

-- 
Lee Hachadoorian
PhD Student, Geography
Program in Earth & Environmental Sciences
CUNY Graduate Center