CREATE TABLESPACE Statement Prior to NDB 8.0.21  the table comment used with  ALTER TABLE  replaced any existing comment which the table might have had. This meant that (for example) the  READ_BACKUP  value was not carried over to the new comment set by the  ALTER TABLE  statement  and that any unspecified values reverted to their defaults. (BUG#30428829) There was thus no longer any way using SQL to retrieve the value previously set for the comment. To keep comment values from reverting to their defaults  it was necessry to preserve any such values from the existing comment string and include them in the comment passed to  ALTER TABLE . You can also see the value of the  PARTITION_BALANCE  option in the output of  ndb_desc .  ndb_desc also shows whether the  READ_BACKUP  and  FULLY_REPLICATED  options are set for the table. See the description of this program for more information. 13.1.21 CREATE TABLESPACE Statement CREATE [UNDO] TABLESPACE  tablespace_name InnoDB and NDB: [ADD DATAFILE ’ file_name ’] [AUTOEXTEND_SIZE [=]  value ] InnoDB only: [FILE_BLOCK_SIZE = value] [ENCRYPTION [=] {’Y’ | ’N’}] NDB only: USE LOGFILE GROUP  logfile_group [EXTENT_SIZE [=]  extent_size ] [INITIAL_SIZE [=]  initial_size ] [MAX_SIZE [=]  max_size ] [NODEGROUP [=]  nodegroup_id ] [WAIT] [COMMENT [=] ’ string ’] InnoDB and NDB: [ENGINE [=]  engine_name ] Reserved for future use: [ENGINE_ATTRIBUTE [=] ’ string ’] This statement is used to create a tablespace. The precise syntax and semantics depend on the storage engine used. In standard MySQL releases  this is always an  InnoDB  tablespace. MySQL NDB Cluster also supports tablespaces using the  NDB  storage engine. •Considerations for InnoDB •Considerations for NDB Cluster •Options •Notes •InnoDB Examples •NDB Example Considerations for InnoDB CREATE TABLESPACE  syntax is used to create general tablespaces or undo tablespaces. The  UNDO keyword  introduced in MySQL 8.0.14  must be specified to create an undo tablespace. 2597