## Conclusion
+ Scenarios of TTL, please refer to：
+ Syntax of TTL, please refer to：
+ Job configuration of TTL, please refer to：
+ Observability of TTL, please refer to：
+ Compatibility of TTL, please refer to：,
+ Limitations of TTL, please refer to：
+ PCTA / PCTP Exam Knowledge Points:
+ TTL does not guarantee that all expired data is deleted immediately, which means that even if some data is expired, the client might still read that data some time after the expiration time until that data is deleted by the background TTL job, please refer to：.
+ How to set TTL attributes using generated columns, please refer to：.
+ `tidb_ttl_job_enable` is used to control whether TTL jobs are enabled. If it is set to OFF, all tables with TTL attributes automatically stop cleaning up expired data. Please refer to：.