text: CREATE TABLE review_flow (
  	review_flow_id SERIAL PRIMARY KEY,
  	course_id INTEGER REFERENCES course ON DELETE CASCADE DEFAULT NULL,
  	exercise_id INTEGER REFERENCES exercise ON DELETE CASCADE DEFAULT NULL,
  	user_id INTEGER REFERENCES app_user ON DELETE CASCADE DEFAULT NULL,
  	title TEXT NOT NULL,
  	description TEXT NOT NULL,
  	tags TEXT[] NOT NULL DEFAULT array[]::TEXT[]
  );
  
  CREATE TYPE review_flow_step_action AS ENUM ('Search', 'Model', 'Review');
  
  CREATE TABLE review_flow_step (
  	review_flow_id INTEGER NOT NULL REFERENCES review_flow ON DELETE CASCADE,
  	index INTEGER NOT NULL,
  	action review_flow_step_action NOT NULL,
  	data JSONB NOT NULL,
  	PRIMARY KEY(review_flow_id, index)
  );
  