Code source de django.contrib.postgres.indexes
from __future__ import unicode_literals
from django.db.models import Index
__all__ = ['BrinIndex', 'GinIndex']
[docs]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(BrinIndex, self).__init__(fields, name)
def __repr__(self):
if self.pages_per_range is not None:
return '<%(name)s: fields=%(fields)s, pages_per_range=%(pages_per_range)s>' % {
'name': self.__class__.__name__,
'fields': "'{}'".format(', '.join(self.fields)),
'pages_per_range': self.pages_per_range,
}
else:
return super(BrinIndex, self).__repr__()
def deconstruct(self):
path, args, kwargs = super(BrinIndex, self).deconstruct()
if self.pages_per_range is not None:
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(BrinIndex, self).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
[docs]class GinIndex(Index):
suffix = 'gin'
def create_sql(self, model, schema_editor):
return super(GinIndex, self).create_sql(model, schema_editor, using=' USING gin')