Replication and Binary Logging Options and Variables • binlog_transaction_dependency_history_size Command-Line Format --binlog-transaction-dependency- history-size=# System Variable binlog_transaction_dependency_history_size Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 25000 Minimum Value 1 Maximum Value 1000000 Sets an upper limit on the number of row hashes which are kept in memory and used for looking up the transaction that last modified a given row. Once this number of hashes has been reached, the history is purged. • expire_logs_days Command-Line Format --expire-logs-days=# Deprecated Yes System Variable expire_logs_days Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 0 Minimum Value 0 Maximum Value 99 Specifies the number of days before automatic removal of binary log files.  expire_logs_days is deprecated, and you should expect it to be removed in a future release. Instead, use binlog_expire_logs_seconds , which sets the binary log expiration period in seconds. If you do not set a value for either system variable, the default expiration period is 30 days. Possible removals happen at startup and when the binary log is flushed. Log flushing occurs as indicated in Section 5.4, “MySQL Server Logs” . Any non-zero value that you specify for  expire_logs_days  is ignored if  binlog_expire_logs_seconds  is also specified, and the value of binlog_expire_logs_seconds  is used instead as the binary log expiration period. A warning message is issued in this situation. A non-zero value for  expire_logs_days  is only applied as the binary log expiration period if  binlog_expire_logs_seconds  is not specified or is specified as 0. To disable automatic purging of the binary log, specify a value of 0 explicitly for binlog_expire_logs_seconds , and do not specify a value for  expire_logs_days . For compatibility with earlier releases, automatic purging is also disabled if you specify a value of 0 explicitly 3562