1CREATE TABLE IF NOT EXISTS "contacts" (
 2    "id" SERIAL PRIMARY KEY,
 3    "user_id_a" INTEGER REFERENCES users (id) NOT NULL,
 4    "user_id_b" INTEGER REFERENCES users (id) NOT NULL,
 5    "a_to_b" BOOLEAN NOT NULL,
 6    "should_notify" BOOLEAN NOT NULL,
 7    "accepted" BOOLEAN NOT NULL
 8);
 9
10CREATE UNIQUE INDEX "index_contacts_user_ids" ON "contacts" ("user_id_a", "user_id_b");
11CREATE INDEX "index_contacts_user_id_b" ON "contacts" ("user_id_b");