InnoDB System Variables Defines the relative path, name, size, and attributes of global temporary tablespace data files. The global temporary tablespace stores rollback segments for changes made to user-created temporary tables. If no value is specified for  innodb_temp_data_file_path , the default behavior is to create a single auto-extending data file named  ibtmp1  in the  innodb_data_home_dir  directory. The initial file size is slightly larger than 12MB. The syntax for a global temporary tablespace data file specification includes the file name, file size, and autoextend  and  max  attributes: The global temporary tablespace data file cannot have the same name as another  InnoDB  data file. Any inability or error creating the global temporary tablespace data file is treated as fatal and server startup is refused. File sizes are specified in KB, MB, or GB by appending  K ,  M  or  G  to the size value. The sum of file sizes must be slightly larger than 12MB. The size limit of individual files is determined by the operating system. File size can be more than 4GB on operating systems that support large files. Use of raw disk partitions for global temporary tablespace data files is not supported. The  autoextend  and  max  attributes can be used only for the data file specified last in the innodb_temp_data_file_path  setting. For example: The  autoextend  option causes the data file to automatically increase in size when it runs out of free space. The  autoextend  increment is 64MB by default. To modify the increment, change the innodb_autoextend_increment  variable setting. The directory path for global temporary tablespace data files is formed by concatenating the paths defined by  innodb_data_home_dir  and  innodb_temp_data_file_path . Before running  InnoDB  in read-only mode, set  innodb_temp_data_file_path  to a location outside of the data directory. The path must be relative to the data directory. For example: For more information, see Global Temporary Tablespace. • innodb_temp_tablespaces_dir file_name : file_size [:autoextend[:max: max_file_size ]] [mysqld] innodb_temp_data_file_path=ibtmp1:50M;ibtmp2:12M:autoextend:max:500MB --innodb-temp-data-file-path=../../../tmp/ibtmp1:12M:autoextend Default Value ibtmp1:12M:autoextend Command-Line Format --innodb-temp-tablespaces- dir=dir_name Introduced 8.0.13 System Variable innodb_temp_tablespaces_dir Scope Global Dynamic No SET_VAR  Hint Applies No 3290