django1/django/contrib/postgres/indexes.py

60 lines
2.5 KiB
Python

from django.db.models import Index
__all__ = ['BrinIndex', 'GinIndex']
class BrinIndex(Index):
suffix = 'brin'
# Allow an index name longer than 30 characters since the suffix is 4
# characters (usual limit is 3). Since this index can only be used on
# PostgreSQL, the 30 character limit for cross-database compatibility isn't
# applicable.
max_name_length = 31
def __init__(self, fields=[], name=None, pages_per_range=None):
if pages_per_range is not None and pages_per_range <= 0:
raise ValueError('pages_per_range must be None or a positive integer')
self.pages_per_range = pages_per_range
super().__init__(fields, name)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
kwargs['pages_per_range'] = self.pages_per_range
return path, args, kwargs
def get_sql_create_template_values(self, model, schema_editor, using):
parameters = super().get_sql_create_template_values(model, schema_editor, using=' USING brin')
if self.pages_per_range is not None:
parameters['extra'] = ' WITH (pages_per_range={})'.format(
schema_editor.quote_value(self.pages_per_range)) + parameters['extra']
return parameters
class GinIndex(Index):
suffix = 'gin'
def __init__(self, fields=[], name=None, fastupdate=None, gin_pending_list_limit=None):
self.fastupdate = fastupdate
self.gin_pending_list_limit = gin_pending_list_limit
super().__init__(fields, name)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
kwargs['fastupdate'] = self.fastupdate
kwargs['gin_pending_list_limit'] = self.gin_pending_list_limit
return path, args, kwargs
def get_sql_create_template_values(self, model, schema_editor, using):
parameters = super().get_sql_create_template_values(model, schema_editor, using=' USING gin')
with_params = []
if self.gin_pending_list_limit is not None:
with_params.append('gin_pending_list_limit = %d' % self.gin_pending_list_limit)
if self.fastupdate is not None:
with_params.append('fastupdate = {}'.format('on' if self.fastupdate else 'off'))
if with_params:
parameters['extra'] = 'WITH ({}) {}'.format(', '.join(with_params), parameters['extra'])
return parameters
def create_sql(self, model, schema_editor):
return super().create_sql(model, schema_editor, using=' USING gin')