The following limitations apply to the use of storage engines with user-defined partitioning of tables.
MERGE storage engine.
User-defined partitioning and the MERGE
storage engine are not compatible. Tables using the
MERGE
storage engine cannot be partitioned.
Partitioned tables cannot be merged.
FEDERATED storage engine.
Partitioning of FEDERATED
tables is not
supported; it is not possible to create partitioned
FEDERATED
tables.
CSV storage engine.
Partitioned tables using the CSV
storage
engine are not supported; it is not possible to create
partitioned CSV
tables.
InnoDB storage engine.
InnoDB
foreign keys and MySQL
partitioning are not compatible. Partitioned
InnoDB
tables cannot have foreign key
references, nor can they have columns referenced by foreign
keys. InnoDB
tables which have or which are
referenced by foreign keys cannot be partitioned.
InnoDB
does not support the use of multiple
disks for subpartitions. (This is currently supported only by
MyISAM
.)
In addition,
ALTER
TABLE ... OPTIMIZE PARTITION
does not work correctly
with partitioned tables that use the InnoDB
storage engine. Use ALTER TABLE ... REBUILD
PARTITION
and ALTER TABLE ... ANALYZE
PARTITION
, instead, for such tables. For more
information, see
ALTER TABLE Partition Operations.
User-defined partitioning and the NDB storage engine (NDB Cluster).
Partitioning by KEY
(including
LINEAR KEY
) is the only type of
partitioning supported for the
NDB
storage engine. It is not
possible under normal circumstances in NDB Cluster to create
an NDB Cluster table using any partitioning type other than
[LINEAR
] KEY
, and
attempting to do so fails with an error.
Exception (not for production): It is
possible to override this restriction by setting the
new
system variable on NDB
Cluster SQL nodes to ON
. If you choose to do
this, you should be aware that tables using partitioning types
other than [LINEAR] KEY
are not supported in
production. In such cases, you can create and use
tables with partitioning types other than KEY
or LINEAR KEY
, but you do this entirely at
your own risk. You should also be aware that this
functionality is now deprecated and subject to removal without
further notice in a future release of NDB Cluster.
The maximum number of partitions that can be defined for an
NDB
table depends on the number of
data nodes and node groups in the cluster, the version of the
NDB Cluster software in use, and other factors. See
NDB and user-defined partitioning,
for more information.
As of MySQL NDB Cluster 7.5.2, the maximum amount of fixed-size
data that can be stored per partition in an
NDB
table is 128 TB. Previously, this was 16
GB.
CREATE TABLE
and
ALTER
TABLE
statements that would cause a user-partitioned
NDB
table not to meet either or
both of the following two requirements are not permitted, and
fail with an error:
The table must have an explicit primary key.
All columns listed in the table's partitioning expression must be part of the primary key.
Exception.
If a user-partitioned NDB
table
is created using an empty column-list (that is, using
PARTITION BY KEY()
or PARTITION BY
LINEAR KEY()
), then no explicit primary key is
required.
Partition selection.
Partition selection is not supported for
NDB
tables. See
Partition Selection, for more
information.
Upgrading partitioned tables.
When performing an upgrade, tables which are partitioned by
KEY
and which use any storage engine other
than NDB
must be dumped and
reloaded.
Same storage engine for all partitions. All partitions of a partitioned table must use the same storage engine and it must be the same storage engine used by the table as a whole. In addition, if one does not specify an engine on the table level, then one must do either of the following when creating or altering a partitioned table:
Do not specify any engine for any partition or subpartition
Specify the engine for all partitions or subpartitions