Server System Variables 0 Minimum Value If a query takes longer than this many seconds, the server increments the  Slow_queries  status variable. If the slow query log is enabled, the query is logged to the slow query log file. This value is measured in real time, not CPU time, so a query that is under the threshold on a lightly loaded system might be above the threshold on a heavily loaded one. The minimum and default values of  long_query_time  are 0 and 10, respectively. The value can be specified to a resolution of microseconds. See Section 5.4.5, “The Slow Query Log” . Smaller values of this variable result in more statements being considered long-running, with the result that more space is required for the slow query log. For very small values (less than one second), the log may grow quite large in a small time. Increasing the number of statements considered long-running may also result in false positives for the “excessive Number of Long Running Processes”  alert in MySQL Enterprise Monitor, especially if Group Replication is enabled. For these reasons, very small values should be used in test environments only, or, in production environments, only for a short period. If set to  1 , all  INSERT ,  UPDATE ,  DELETE , and  LOCK TABLE WRITE  statements wait until there is no pending  SELECT  or  LOCK TABLE READ  on the affected table. The same effect can be obtained using {INSERT | REPLACE | DELETE | UPDATE} LOW_PRIORITY ...  to lower the priority of only one query. This variable affects only storage engines that use only table-level locking (such as  MyISAM , MEMORY , and  MERGE ). See Section 8.11.2, “Table Locking Issues” . As of MySQL 8.0.26, setting the session value of this system variable is a restricted operation. The session user must have privileges sufficient to set restricted session variables. See Section 5.1.9.1, “System Variable Privileges” . This variable describes the case sensitivity of file names on the file system where the data directory is located.  OFF  means file names are case-sensitive,  ON  means they are not case-sensitive. This variable is read only because it reflects a file system attribute and setting it would have no effect on the file system. Command-Line Format --low-priority-updates[={OFF|ON}] System Variable low_priority_updates Scope Global, Session Dynamic Yes SET_VAR  Hint Applies No Type Boolean Default Value OFF System Variable lower_case_file_system Scope Global Dynamic No SET_VAR  Hint Applies No Type Boolean • lower_case_file_system • low_priority_updates 825