TablespacesΒΆ
A common paradigm for optimizing performance in database systems is the use of tablespaces to organize disk layout.
Warning
Django does not create the tablespaces for you. Please refer to your database engineβs documentation for details on creating and managing tablespaces.
Declaring tablespaces for tablesΒΆ
A tablespace can be specified for the table generated by a model by supplying
the db_tablespace
option inside the modelβs
class Meta
. This option also affects tables automatically created for
ManyToManyField
s in the model.
You can use the DEFAULT_TABLESPACE
setting to specify a default
value for db_tablespace
. This is useful for
setting a tablespace for the built-in Django apps and other applications whose
code you cannot control.
Declaring tablespaces for indexesΒΆ
You can pass the db_tablespace
option to an
Index
constructor to specify the name of a tablespace to use for the index.
For single field indexes, you can pass the
db_tablespace
option to a Field
constructor
to specify an alternate tablespace for the fieldβs column index. If the column
doesnβt have an index, the option is ignored.
You can use the DEFAULT_INDEX_TABLESPACE
setting to specify
a default value for db_tablespace
.
If db_tablespace
isnβt specified and you didnβt
set DEFAULT_INDEX_TABLESPACE
, the index is created in the same
tablespace as the tables.
An exampleΒΆ
class TablespaceExample(models.Model):
name = models.CharField(max_length=30, db_index=True, db_tablespace="indexes")
data = models.CharField(max_length=255, db_index=True)
shortcut = models.CharField(max_length=7)
edges = models.ManyToManyField(to="self", db_tablespace="indexes")
class Meta:
db_tablespace = "tables"
indexes = [models.Index(fields=["shortcut"], db_tablespace="other_indexes")]
In this example, the tables generated by the TablespaceExample
model (i.e.
the model table and the many-to-many table) would be stored in the tables
tablespace. The index for the name field and the indexes on the many-to-many
table would be stored in the indexes
tablespace. The data
field would
also generate an index, but no tablespace for it is specified, so it would be
stored in the model tablespace tables
by default. The index for the
shortcut
field would be stored in the other_indexes
tablespace.
Database supportΒΆ
PostgreSQL and Oracle support tablespaces. SQLite, MariaDB and MySQL donβt.
When you use a backend that lacks support for tablespaces, Django ignores all tablespace-related options.