1CREATE TABLE pages 2( 3 page TEXT NOT NULL PRIMARY KEY, 4 lastmod INT NOT NULL 5); 6 7CREATE TABLE acks 8( 9 page TEXT NOT NULL REFERENCES pages (page) ON DELETE CASCADE, 10 user TEXT NOT NULL, 11 ack INT NOT NULL, 12 PRIMARY KEY (page, user) 13); 14 15CREATE TABLE assignments 16( 17 page TEXT NOT NULL REFERENCES pages (page) ON DELETE CASCADE PRIMARY KEY, 18 assignee TEXT NOT NULL 19); 20