Oracle 5.0 Reference Manual page 2908

• Temporary tables are not supported; a
or
ENGINE=NDBCLUSTER
• indexes are not supported.
FULLTEXT
• Index prefixes are not supported. Only complete columns may be indexed.
• As of MySQL 5.0.16, MySQL Cluster supports spatial data types. However, spatial indexes are not
supported. See Section 12.16, "Spatial
• Only complete rollbacks for transactions are supported. Partial rollbacks and rollbacks to savepoints
are not supported. A failed insert due to a duplicate key or similar error causes a transaction to abort;
when this occurs, you must issue an explicit
• The maximum number of attributes allowed per table is 128, and attribute names cannot be any
longer than 31 characters. For each table, the maximum combined length of the table and database
names is 122 characters.
• The maximum size for a table row is 8 kilobytes, not counting
There is no set limit for the number of rows per
of factors, in particular on the amount of RAM available to each data node.
• The engine does not support foreign key constraints. As with
NDB
specified in a
CREATE TABLE
For a complete listing of limitations in MySQL Cluster, see
MySQL Cluster". See also
5.0".
B.10.24: How do I import an existing MySQL database into a MySQL Cluster?
You can import databases into MySQL Cluster much as you would with any other version of MySQL.
Other than the limitations mentioned elsewhere in this FAQ, the only other special requirement is that
any tables to be included in the cluster must use the
must be created with
ENGINE=NDB
It is also possible to convert existing tables that use other storage engines to
or more
ALTER TABLE
storage engine prior to making the conversion. In MySQL 5.0, an additional workaround
NDBCLUSTER
is also required; see Section 17.1.5, "Known Limitations of MySQL
B.10.25: How do MySQL Cluster nodes communicate with one another?
Cluster nodes can communicate through any of three different transport mechanisms: TCP/IP, SHM
(shared memory), and SCI (Scalable Coherent Interface). Where available, SHM is used by default
between nodes residing on the same cluster host; however, this is considered experimental. SCI is a
high-speed (1 gigabit per second and higher), high-availability protocol used in building scalable multi-
processor systems; it requires special hardware and drivers. See
Interconnects with MySQL
Cluster.
B.10.26: What is an arbitrator?
If one or more data nodes in a cluster fail, it is possible that not all cluster data nodes will be able
to "see" one another. In fact, it is possible that two sets of data nodes might become isolated from
one another in a network partitioning, also known as a "split-brain" scenario. This type of situation
is undesirable because each set of data nodes tries to behave as though it is the entire cluster. An
arbitrator is required to decide between the competing sets of data nodes.
When all data nodes in at least one node group are alive, network partitioning is not an issue, because
no single subset of the cluster can form a functional cluster on its own. The real problem arises when
MySQL 5.0 FAQ: MySQL Cluster
CREATE TEMPORARY TABLE
fails with an error.
Extensions".
or
ALTER TABLE
Section 17.1.5.10, "Previous MySQL Cluster Issues Resolved in MySQL
or ENGINE=NDBCLUSTER.
statement. However, the definition of the table must be compatible with the
Cluster", for more about using SCI as a transport mechanism for MySQL
2888
and retry the transaction.
ROLLBACK
BLOB
table. Limits on table size depend on a number
NDB
MyISAM
statement, they are ignored.
Section 17.1.5, "Known Limitations of
storage engine. This means that the tables
NDB
Cluster", for details.
Section 17.3.5, "Using High-Speed
statement using
ENGINE=NDB
values.
tables, if these are
using one
NDBCLUSTER