CREATE TABLE doc_links (
    link VARCHAR(255) UNIQUE NOT NULL, -- Unique constraint on the link field
    date_last_modified DATE,
    date_last_visited DATE
);

CREATE TABLE gcp_links (
    link VARCHAR(255) UNIQUE NOT NULL, -- Unique constraint on the link field
    date_last_modified DATE default null,
    date_last_visited DATE default '1970-01-01'
);