ALTER TABLE forward_sessions ADD COLUMN client_id TEXT
    CHECK (
        client_id IS NULL
        OR (length(client_id) BETWEEN 1 AND 32 AND client_id NOT GLOB '*[^a-z0-9_]*')
    );
ALTER TABLE forward_sessions ADD COLUMN address TEXT
    CHECK (
        address IS NULL
        OR (length(address) BETWEEN 2 AND 45 AND address NOT GLOB '*[^0-9a-f.:]*')
    );
ALTER TABLE forward_sessions ADD COLUMN user_agent TEXT
    CHECK (
        user_agent IS NULL
        OR (
            length(CAST(user_agent AS BLOB)) BETWEEN 1 AND 256
            AND user_agent NOT GLOB '*[' || char(1) || '-' || char(31) || char(127) || ']*'
        )
    );
ALTER TABLE forward_sessions ADD COLUMN last_seen_at INTEGER;