• Attributes per key.   The maximum number of attributes per key is 32. • Row size.   Beginning with NDB 8.0.18, the maximum permitted size of any one row is 30000 bytes, in NDB 8.0.17 and earlier releases, this limit is 14000 bytes. Known Limitations of NDB Cluster Each  BLOB  or  TEXT  column contributes 256 + 8 = 264 bytes to this total; this includes  JSON  columns. See String Type Storage Requirements, as well as JSON Storage Requirements, for more information relating to these types. In addition, the maximum offset for a fixed-width column of an  NDB  table is 8188 bytes; attempting to create a table that violates this limitation fails with NDB error 851  Maximum offset for fixed- size columns exceeded . For memory-based columns, you can work around this limitation by using a variable-width column type such as  VARCHAR  or defining the column as  COLUMN_FORMAT=DYNAMIC ; this does not work with columns stored on disk. For disk-based columns, you may be able to do so by reordering one or more of the table’s disk-based columns such that the combined width of all but the disk-based column defined last in the  CREATE TABLE  statement used to create the table does not exceed 8188 bytes, less any possible rounding performed for some data types such as  CHAR  or VARCHAR ; otherwise it is necessary to use memory-based storage for one or more of the offending column or columns instead. • BIT column storage per table.   The maximum combined width for all  BIT  columns used in a given NDB  table is 4096. • FIXED column storage.   NDB Cluster 8.0 supports a maximum of 128 TB per fragment of data in FIXED  columns. • Index prefixes.   Prefixes on indexes are not supported for  NDB  tables. If a prefix is used as part of an index specification in a statement such as  CREATE TABLE ,  ALTER TABLE , or  CREATE INDEX , the prefix is not created by  NDB . 23.1.7.6 Unsupported or Missing Features in NDB Cluster A number of features supported by other storage engines are not supported for  NDB  tables. Trying to use any of these features in NDB Cluster does not cause errors in or of itself; however, errors may occur in applications that expects the features to be supported or enforced. Statements referencing such features, even if effectively ignored by  NDB , must be syntactically and otherwise valid. A statement containing an index prefix, and creating or modifying an  NDB  table, must still be syntactically valid. For example, the following statement always fails with Error 1089  Incorrect prefix key; the used key part isn’t a string, the used length is longer than the key part, or the storage engine doesn’t support unique prefix keys , regardless of storage engine: This happens on account of the SQL syntax rule that no index may have a prefix larger than itself. 3972 • Savepoints and rollbacks.   Savepoints and rollbacks to savepoints are ignored as in  MyISAM . • Durability of commits.   There are no durable commits on disk. Commits are replicated, but there is no guarantee that logs are flushed to disk on commit. CREATE TABLE t1 ( c1 INT NOT NULL, c2 VARCHAR(100), INDEX i1 (c2(500)) );