InnoDB System Variables long-running back-end operations, such as a transform step in a data warehouse that waits for other large insert or update operations to finish. innodb_lock_wait_timeout  applies to  InnoDB  row locks. A MySQL table lock does not happen inside  InnoDB  and this timeout does not apply to waits for table locks. The lock wait timeout value does not apply to deadlocks when  innodb_deadlock_detect is enabled (the default) because  InnoDB  detects deadlocks immediately and rolls back one of the deadlocked transactions. When  innodb_deadlock_detect  is disabled,  InnoDB  relies on innodb_lock_wait_timeout  for transaction rollback when a deadlock occurs. See Section 15.7.5.2, “Deadlock Detection” . innodb_lock_wait_timeout  can be set at runtime with the  SET GLOBAL  or  SET SESSION statement. Changing the  GLOBAL  setting requires privileges sufficient to set global system variables (see Section 5.1.9.1, “System Variable Privileges” ) and affects the operation of all clients that subsequently connect. Any client can change the  SESSION  setting for  innodb_lock_wait_timeout , which affects only that client. The size in bytes of the buffer that  InnoDB  uses to write to the log files on disk. The default is 16MB. A large log buffer enables large transactions to run without the need to write the log to disk before the transactions commit. Thus, if you have transactions that update, insert, or delete many rows, making the log buffer larger saves disk I/O. For related information, see Memory Configuration, and Section 8.5.4, “Optimizing InnoDB Redo Logging” . For general I/O tuning advice, see Section 8.5.8, “Optimizing InnoDB Disk I/O” . • innodb_log_checkpoint_fuzzy_now • innodb_log_buffer_size Command-Line Format --innodb-log-buffer-size=# System Variable innodb_log_buffer_size Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 16777216 Minimum Value 1048576 Maximum Value 4294967295 Command-Line Format --innodb-log-checkpoint-fuzzy- now[={OFF|ON}] Introduced 8.0.13 System Variable innodb_log_checkpoint_fuzzy_now Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Boolean 3257