The temporary tablespace is used for non-compressed
InnoDB temporary tables and related objects.
configuration option defines a relative path for the temporary
tablespace data file. If
innodb_temp_data_file_path is not
defined, a single auto-extending 12MB data file named
ibtmp1 is created in the data directory. The
temporary tablespace is recreated on each server start and
receives a dynamically generated space ID, which helps avoid
conflicts with existing space IDs. The temporary tablespace cannot
reside on a raw device. Startup is refused if the temporary
tablespace cannot be created.
The temporary tablespace is removed on normal shutdown or on an aborted initialization. The temporary tablespace is not removed when a crash occurs. In this case, the database administrator may remove the temporary tablespace manually or restart the server with the same configuration, which removes and recreates the temporary tablespace.
provides metadata about active
tables. With the exception of optimized internal temporary tables
INNODB_TEMP_TABLE_INFO reports on all
user and system-created temporary tables that are active within a
Temporary table undo logs are used for temporary tables and related objects. This type of undo log is not a redo log, as temporary tables are not recovered during crash recovery and do not require redo logs. Temporary table undo logs are, however, used for rollback while the server is running. This special type of non-redo undo log benefits performance by avoiding redo logging I/O for temporary tables and related objects. Temporary table undo logs reside in the temporary tablespace. 32 rollback segments are reserved for temporary table undo logs for transactions that modify temporary tables and related objects.