# Multiple Choice Questions

+ Which of the following statement(s) is/are correct for the TiDB configuration file parameters?
  + A. The modified TiKV configuration file parameters will only take effects after restarting the TiKV nodes.
  + B. TiDB configuration file parameters have scopes.
  + C. You may change the TiDB configuration file parameters via MySQL clients.
  + D. Some of the configuration file parameters are persisted in the configuration files of TiDB, TiKV, and PD, while others are persisted in the TiKV storage.

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+ Answers: C
+ A is wrong. Some TiKV configuration file parameters can be changed dynamically, such as `split.qps-threshold` mentioned previously.
+ B is wrong. Only system variables has scope.
+ C is correct.
+ D is wrong. Only system variables are persisted to TiKV.