A number of features supported by other storage engines are not
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
Foreign key constraints. Prior to NDB Cluster 7.3, the foreign key construct is ignored, just as it is by
MyISAMtables. Foreign keys are supported in NDB Cluster 7.3 and later.
Index prefixes. Prefixes on indexes are not supported for
NDBtables. If a prefix is used as part of an index specification in a statement such as
ALTER TABLE, or
CREATE INDEX, the prefix is not created by
A statement containing an index prefix, and creating or modifying an
NDBtable, 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:
CREATE TABLE t1 ( c1 INT NOT NULL, c2 VARCHAR(100), INDEX i1 (c2(500)) );
This happens on account of the SQL syntax rule that no index may have a prefix larger than itself.
Savepoints and rollbacks. Savepoints and rollbacks to savepoints are ignored as in
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.
Replication. Statement-based replication is not supported. Use
--binlog-format=MIXED) when setting up cluster replication. See Section 18.6, “NDB Cluster Replication”, for more information.
Semisynchronous replication is not supported in NDB Cluster.
See Section 126.96.36.199, “Limits Relating to Transaction Handling in NDB Cluster”,
for more information relating to limitations on transaction