What happens when DB engine runs out of numbers to use for primary keys?

Question

Since DBs do not reuse numbers of deleted records it is possible to run out of numbers, especially if you pick not really a big integer type for this column.
What would

Answer 1

Oracle doesn't support autoincrementing ID columns and standard practice is to use a sequence generator. A sequence generates integers of up to 28 digits, so if you run out of those then ... I guess you have a pretty big table. But behaviour would then be dependent on the configuration of the sequence generator -- either an error or it would cycle back to the start value and you'd get a PK constraint violation on the next insert.