This will ensure the ID never exceeds the max size. With Serial, the DB can only handle 2 billion rows, which is not that much for a db. By switching to Big Serial, there is no longer any reason to worry about the limit being reached. All for the small cost of using an additional 4bytes per ID.
ondras
commented
7 years ago
This will ensure the ID never exceeds the max size. With Serial, the DB can only handle 2 billion rows, which is not that much for a db. By switching to Big Serial, there is no longer any reason to worry about the limit being reached. All for the small cost of using an additional 4bytes per ID.
See this article