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.
Foreign key constraints.
Prior to NDB Cluster 7.3, the foreign key construct is
ignored, just as it is by MyISAM
tables. Foreign keys are supported in NDB Cluster 7.3 and
later.
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.
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:
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
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.
Replication.
Statement-based replication is not supported. Use
--binlog-format=ROW (or
--binlog-format=MIXED) when
setting up cluster replication. See
Section 18.6, “NDB Cluster Replication”, for more
information.
See Section 18.1.6.3, “Limits Relating to Transaction Handling in NDB Cluster”,
for more information relating to limitations on transaction
handling in NDB.