Some SQL statements relating to certain MySQL features produce
errors when used with
as described in the following list:
Temporary tables. Temporary tables are not supported. Trying either to create a temporary table that uses the
NDBstorage engine or to alter an existing temporary table to use
NDBfails with the error Table storage engine 'ndbcluster' does not support the create option 'TEMPORARY'.
Indexes and keys in NDB tables. Keys and indexes on MySQL Cluster tables are subject to the following limitations:
Column width. Attempting to create an index on an
NDBtable column whose width is greater than 3072 bytes succeeds, but only the first 3072 bytes are actually used for the index. In such cases, a warning Specified key was too long; max key length is 3072 bytes is issued, and a
SHOW CREATE TABLEstatement shows the length of the index as 3072.
FULLTEXT indexes. The
NDBstorage engine does not support
FULLTEXTindexes, which are possible for
USING HASH keys and NULL. Using nullable columns in unique keys and primary keys means that queries using these columns are handled as full table scans. To work around this issue, make the column
NOT NULL, or re-create the index without the
Prefixes. There are no prefix indexes; only entire columns can be indexed. (The size of an
NDBcolumn index is always the same as the width of the column in bytes, up to and including 3072 bytes, as described earlier in this section. Also see Section 188.8.131.52, “Unsupported or Missing Features in MySQL Cluster”, for additional information.)
BIT columns. A
BITcolumn cannot be a primary key, unique key, or index, nor can it be part of a composite primary key, unique key, or index.
AUTO_INCREMENT columns. Like other MySQL storage engines, the
NDBstorage engine can handle a maximum of one
AUTO_INCREMENTcolumn per table. However, in the case of a Cluster table with no explicit primary key, an
AUTO_INCREMENTcolumn is automatically defined and used as a “hidden” primary key. For this reason, you cannot define a table that has an explicit
AUTO_INCREMENTcolumn unless that column is also declared using the
PRIMARY KEYoption. Attempting to create a table with an
AUTO_INCREMENTcolumn that is not the table's primary key, and using the
NDBstorage engine, fails with an error.
MySQL Cluster and geometry data types. Geometry data types (
WKB) are supported in
NDBtables in MySQL 5.0. However, spatial indexes are not supported.