What is New in NDB Cluster to pool transactional and Local Data Manager (LDM) memory. This parameter is intended to replace several older transactional memory parameters which have been deprecated. Transaction memory can now be set in any of the three ways listed here: •Several configuration parameters are incompatible with  TransactionMemory . If any of these are set, TransactionMemory  cannot be set (see Parameters incompatible with TransactionMemory), and the data node’s transaction memory is determined as it was previous to NDB 8.0.19. Attempting to set  TransactionMemory  and any of these parameters concurrently in the  config.ini  file prevents the management server from starting. Note •If  TransactionMemory  is set, this value is used for determining transaction memory. TransactionMemory  cannot be set if any of the incompatible parameters mentioned in the previous item have also been set. •If none of the incompatible parameters are set and  TransactionMemory  is also not set, transaction memory is set by  NDB . For more information, see the description of  TransactionMemory , as well as Section 23.3.3.13, “Data Node Memory Management” . • Support for additional fragment replicas.   NDB 8.0.19 increases the maximum number of fragment replicas supported in production from two to four. (Previously, it was possible to set  NoOfReplicas  to 3 or 4, but this was not officially supported or verified in testing.) • Restoring by slices.   Beginning with NDB 8.0.20, it is possible to divide a backup into roughly equal portions (slices) and to restore these slices in parallel using two new options implemented for ndb_restore : • --num-slices  determines the number of slices into which the backup should be divided. • --slice-id  provides the ID of the slice to be restored by the current instance of  ndb_restore . This makes it possible to employ multiple instances of  ndb_restore  to restore subsets of the backup in parallel, potentially reducing the amount of time required to perform the restore operation. For more information, see the description of the  ndb_restore --num-slices  option. • Read from any fragment replica enabled.   Beginning with NDB 8.0.19, read from any fragment replica is enabled by default for all  NDB  tables. This means that the default value for the ndb_read_backup  system variable is now ON, and that the value of the  NDB_TABLE  comment option READ_BACKUP  is 1 when creating a new  NDB  table. Enabling read from any fragment replica significantly improves performance for reads from  NDB  tables, with minimal impact on writes. • ndb_blob_tool enhancements.   Beginning with NDB 8.0.20, the  ndb_blob_tool  utility can detect missing blob parts for which inline parts exist and replace these with placeholder blob parts (consisting of space characters) of the correct length. To check whether there are missing blob parts, use the  -- For more information, see the description of the  ndb_read_backup  system variable, and Section 13.1.20.11, “Setting NDB_TABLE Options” . 3945