Communication Logs: Handling 250M SMS messages a day

    CREATE TABLE friendship (
     person1 INT NOT NULL,
     person2 INT NOT NULL,
     PRIMARY KEY (person1, person2),
     CHECK (person1 < person2)
    );
    CREATE INDEX friendship_person2 ON friendship(person2);


    CREATE VIEW friendship_view AS
    SELECT person1 AS person, person2 AS friend 
    FROM friendship
    UNION
    SELECT person2 AS person, person1 AS friend FORM friendship;

What do you folks think? It seems like this would be the densest way to store the relationship, using the checked constraint trick with the IDs so you don't need duplicate records to store Alice and Bob's friendship as {A -> B, B -> A} if the friendship is inherently bidirectional (vs a followed/follower model), and doesn't preclude one from storing the data in another isomorphic structure that might be optimized for specific queries. I'm sure it's possible to replicate this with Neo4j, but it felt cumbersome programming that in Java versus expressing that in SQL. But I'd really like to use Neo4j in an OLTP environment, but still haven't had enough of an impetus yet because WITH RECURSIVE in postgres works well if the recursion depth is capped.

I certainly hope your system can manage 400kBps throughput.