Continuous Sequence Gaps & Recovery:
"You notice that an Invoice ID sequence, configured as continuous, still shows a gap in the numbering after an integration process crashed. What might have happened, and how can gaps occur even in continuous sequences? What steps can be taken to prevent or fix such gaps if required for compliance?"
Interviewer guidance: The candidate should recall that a continuous sequence tries not to skip, but a crash can still cause a number to appear lost until the system recycles it. The missing number might be held for a failed transaction and will be reused only after a cleanup job runs or as part of system recovery for continuous sequences. To ensure no permanent gaps, you might need to run the automatic cleanup (or confirm it's configured to run) after such failures. Look for mention of how continuous sequences differ in this behavior (they attempt to recycle on failure, unlike noncontinuous) and that if immediate strict sequence is needed, a manual fallback could be necessary (though usually the built-in mechanism covers it).