InnoDB System Variables SET_VAR  Hint Applies No Type Boolean Default Value OFF Command-Line Format --innodb-trx-rseg-n-slots-debug=# System Variable innodb_trx_rseg_n_slots_debug Scope Global Dynamic Yes SET_VAR  Hint Applies No Type Integer Default Value 0 Maximum Value 1024 Command-Line Format --innodb-undo-directory=dir_name System Variable innodb_undo_directory Scope Global Dynamic No SET_VAR  Hint Applies No Type Directory name Pauses purging of delete-marked records while allowing the purge view to be updated. This option artificially creates a situation in which the purge view is updated but purges have not yet been performed. This option is only available if debugging support is compiled in using the  WITH_DEBUG CMake  option. Sets a debug flag that limits  TRX_RSEG_N_SLOTS  to a given value for the trx_rsegf_undo_find_free  function that looks for free slots for undo log segments. This option is only available if debugging support is compiled in using the  WITH_DEBUG CMake  option. The path where  InnoDB  creates undo tablespaces. Typically used to place undo tablespaces on a different storage device. There is no default value (it is NULL). If the  innodb_undo_directory  variable is undefined, undo tablespaces are created in the data directory. The default undo tablespaces ( innodb_undo_001  and  innodb_undo_002 ) created when the MySQL instance is initialized always reside in the directory defined by the  innodb_undo_directory  variable. Undo tablespaces created using  CREATE UNDO TABLESPACE  syntax are created in the directory defined by the  innodb_undo_directory  variable if a different path is not specified. For more information, see Section 15.6.3.4, “Undo Tablespaces” . 3294 • innodb_trx_rseg_n_slots_debug • innodb_undo_directory