Database migration operations¶
All of these operations are available from
Creating extension using migrations¶
You can create a PostgreSQL extension in your database using a migration file. This example creates an hstore extension, but the same principles apply for other extensions.
from django.contrib.postgres.operations import HStoreExtension class Migration(migrations.Migration): ... operations = [ HStoreExtension(), ... ]
The operation skips adding the extension if it already exists.
For most extensions, this requires a database user with superuser privileges.
If the Django database user doesn’t have the appropriate privileges, you’ll
have to create the extension outside of Django migrations with a user that has
them. In that case, connect to your Django database and run the query
CREATE EXTENSION IF NOT EXISTS hstore;.
In older versions, the pre-existence of the extension isn’t checked.
hstoreextension and also sets up the connection to interpret hstore data for possible use in subsequent migrations.
Managing collations using migrations¶
If you need to filter or order a column using a particular collation that your
operating system provides but PostgreSQL does not, you can manage collations in
your database using a migration file. These collations can then be used with
db_collation parameter on
TextField, and their subclasses.
For example, to create a collation for German phone book ordering:
from django.contrib.postgres.operations import CreateCollation class Migration(migrations.Migration): ... operations = [ CreateCollation( 'german_phonebook', provider='icu', locale='und-u-ks-level2', ), ... ]
CreateCollation(name, locale, *, provider='libc', deterministic=True)¶
Creates a collation with the given
Falseto create a non-deterministic collation, such as for case-insensitive filtering.
RemoveCollation(name, locale, *, provider='libc', deterministic=True)¶
Removes the collations named
When reversed this is creating a collation with the provided
localeis required to make this operation reversible.
PostgreSQL 9.6 only supports the
Non-deterministic collations are supported only on PostgreSQL 12+.
Concurrent index operations¶
PostgreSQL supports the
CONCURRENTLY option to
CREATE INDEX and
DROP INDEX statements to add and remove indexes without locking out writes.
This option is useful for adding or removing an index in a live production
AddIndex, but creates an index with the
CONCURRENTLYoption. This has a few caveats to be aware of when using this option, see the PostgreSQL documentation of building indexes concurrently.
CONCURRENTLY option is not supported inside a transaction (see