# Mysql Database (Continue...)
+ `mysql.GLOBAL_VARIABLES` 
  + View TiDB global variables through the system table
  + Supports modify of VARIABLE_VALUE in the system table

+ `mysql.tidb` 
  + A table that stores the status of the cluster as keyValues
  + The relevant system behavior can be adjusted by modify the relevant VARIABLE_VALUE in mysql.tidb

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MySQL.global_variables
- View TiDB global variables through the system table
- Support modify of VARIABLE_VALUE in the system table
mysql.tidb
- mysql.tidb is a table that stores the status of the cluster in the form of Key\ Value
- At first, this system table is only a system table that sets the status of whether the tidb cluster is bootstrapped
- Control switches such as tikv_gc_enable and tikv_gc_life_time were added with the TiDB version change
- Related system behavior can be adjusted by modify the relevant VARIABLE_VALUE in mysql.tidb