[maxgee]

Nothing. Integers are simpler and faster. They're also incorrect about COUNTs requiring a full record scan.

[xkqd]

How are integers simpler? Even generation of unique integers is more complicated, let alone migrating them or moving them around.

[catlifeonmars]

1. You have to handle race conditions if there is ever more than one process writing to the DB at one time 2. It’s ambiguous whether a number is an ID. E.g. when looking at logs 3. Numbers leak information about table size, row age, and crucially future row IDs.

[phito]

Nothing? Really? Have you ever thought about that?