Server System Variables Dynamic Yes SET_VAR  Hint Applies Yes Type Integer Default Value 31536000 Minimum Value 1 Maximum Value 31536000 This variable specifies the timeout in seconds for attempts to acquire metadata locks. The permissible values range from 1 to 31536000 (1 year). The default is 31536000. This timeout applies to all statements that use metadata locks. These include DML and DDL operations on tables, views, stored procedures, and stored functions, as well as  LOCK TABLES ,  FLUSH TABLES WITH READ LOCK , and  HANDLER  statements. This timeout does not apply to implicit accesses to system tables in the  mysql  database, such as grant tables modified by  GRANT  or  REVOKE  statements or table logging statements. The timeout does apply to system tables accessed directly, such as with  SELECT  or  UPDATE . The timeout value applies separately for each metadata lock attempt. A given statement can require more than one lock, so it is possible for the statement to block for longer than the  lock_wait_timeout value before reporting a timeout error. When lock timeout occurs,  ER_LOCK_WAIT_TIMEOUT  is reported. lock_wait_timeout  also defines the amount of time that a  LOCK INSTANCE FOR BACKUP statement waits for a lock before giving up. Whether  mysqld  was locked in memory with  --memlock . System Variable locked_in_memory Scope Global Dynamic No SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --log-error[=file_name] System Variable log_error Scope Global Dynamic No SET_VAR  Hint Applies No Type File name The default error log destination. If the destination is the console, the value is  stderr . Otherwise, the destination is a file and the  log_error  value is the file name. See Section 5.4.2, “The Error Log” . 818 • log_error • locked_in_memory