This section applies only to NDB Cluster in MySQL 5.1 and later. Previous versions of MySQL did not support Disk Data tables.
NDB Cluster Disk Data files are created (or dropped) by the user by means of SQL statements intended specifically for this purpose. Such files include the following:
One or more undo logfiles associated with a logfile group
One or more datafiles associated with a tablespace that uses the logfile group for undo logging
Both undo logfiles and datafiles are created in the data
each cluster data node. The relationship of these files with
their logfile group and tablespace are shown in the following
Disk Data files and the SQL commands used to create and drop them are discussed in depth in NDB Cluster Disk Data Tables.