PostgreSQL specific model indexes
 New in Django 1.11. 
 The following are PostgreSQL specific indexes available from the django.contrib.postgres.indexes module.
BrinIndex
 - 
class BrinIndex(fields=[], name=None, pages_per_range=None)[source]
- 
Creates a BRIN index. The pages_per_rangeargument takes a positive integer.
GinIndex
 - 
class GinIndex[source]
- 
Creates a gin index. To use this index on data types not in the built-in operator classes, you need to activate the btree_gin extension on PostgreSQL. You can install it using the BtreeGinExtensionmigration operation.
    © Django Software Foundation and individual contributors
Licensed under the BSD License.
    https://docs.djangoproject.com/en/1.11/ref/contrib/postgres/indexes/