30.4.4.4 ps_setup_disable_background_threads() 过程
禁用所有后台线程的性能模式检测。生成一个结果集，指示禁用了多少个后台线程。已禁用的线程不计数。
mysql> CALL sys.ps_setup_disable_background_threads();
+--------------------------------+
| summary |
+--------------------------------+
| Disabled 24 background threads |
+--------------------------------+