Known Limitations of NDB Cluster •A  DROP TABLE  or  TRUNCATE TABLE  operation on an  NDB  table frees the memory that was used by this table for re-use by any  NDB  table, either by the same table or by another  NDB  table. • Limits imposed by the cluster’s configuration.  •Database memory size and index memory size ( DataMemory  and  IndexMemory , respectively). •The maximum number of operations that can be performed per transaction is set using the configuration parameters  MaxNoOfConcurrentOperations  and  MaxNoOfLocalOperations . •Different limits related to tables and indexes. For example, the maximum number of ordered indexes in the cluster is determined by  MaxNoOfOrderedIndexes , and the maximum number of ordered indexes per table is 16. • Node and data object maximums.   The following limits apply to numbers of cluster nodes and metadata objects: •As of NDB 8.0.18, the maximum number of data nodes is 145. (Previously, this was 48.) •The total maximum number of nodes in an NDB Cluster is 255. This number includes all SQL nodes (MySQL Servers), API nodes (applications accessing the cluster other than MySQL servers), data nodes, and management servers. •The maximum number of metadata objects in current versions of NDB Cluster is 20320. This limit is hard-coded. 3968 23.1.7.3 Limits Relating to Transaction Handling in NDB Cluster A number of limitations exist in NDB Cluster with regard to the handling of transactions. These include the following: See Section 23.1.7.11, “Previous NDB Cluster Issues Resolved in NDB Cluster 8.0” , for more information. Management and API nodes may use node IDs in the range 1 to 255, inclusive. A data node must have a node ID in the range of 1 to 144, inclusive. (In NDB 8.0.17 and earlier releases, this was 1 to 48, inclusive.) Bulk loading,  TRUNCATE TABLE , and  ALTER TABLE  are handled as special cases by running multiple transactions, and so are not subject to this limitation. Note Note Recall that  TRUNCATE TABLE  drops and re-creates the table. See Section 13.1.37, “TRUNCATE TABLE Statement” . A number of hard limits exist which are configurable, but available main memory in the cluster sets limits. See the complete list of configuration parameters in Section 23.3.3, “NDB Cluster Configuration Files” . Most configuration parameters can be upgraded online. These hard limits include: DataMemory  is allocated as 32KB pages. As each  DataMemory  page is used, it is assigned to a specific table; once allocated, this memory cannot be freed except by dropping the table. See Section 23.3.3.6, “Defining NDB Cluster Data Nodes” , for more information.