from django.db import NotSupportedError
from django.db.models import Func, Index
from django.utils.functional import cached_property
__all__ = [
'BloomIndex', 'BrinIndex', 'BTreeIndex', 'GinIndex', 'GistIndex',
'HashIndex', 'SpGistIndex',
]
class PostgresIndex(Index):
@cached_property
def max_name_length(self):
# Allow an index name longer than 30 characters when the suffix is
# longer than the usual 3 character limit. The 30 character limit for
# cross-database compatibility isn't applicable to PostgreSQL-specific
# indexes.
return Index.max_name_length - len(Index.suffix) + len(self.suffix)
def create_sql(self, model, schema_editor, using='', **kwargs):
self.check_supported(schema_editor)
statement = super().create_sql(model, schema_editor, using=' USING %s' % self.suffix, **kwargs)
with_params = self.get_with_params()
if with_params:
statement.parts['extra'] = 'WITH (%s) %s' % (
', '.join(with_params),
statement.parts['extra'],
)
return statement
def check_supported(self, schema_editor):
pass
def get_with_params(self):
return []
[документация]class BloomIndex(PostgresIndex):
suffix = 'bloom'
def __init__(self, *expressions, length=None, columns=(), **kwargs):
super().__init__(*expressions, **kwargs)
if len(self.fields) > 32:
raise ValueError('Bloom indexes support a maximum of 32 fields.')
if not isinstance(columns, (list, tuple)):
raise ValueError('BloomIndex.columns must be a list or tuple.')
if len(columns) > len(self.fields):
raise ValueError(
'BloomIndex.columns cannot have more values than fields.'
)
if not all(0 < col <= 4095 for col in columns):
raise ValueError(
'BloomIndex.columns must contain integers from 1 to 4095.',
)
if length is not None and not 0 < length <= 4096:
raise ValueError(
'BloomIndex.length must be None or an integer from 1 to 4096.',
)
self.length = length
self.columns = columns
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.length is not None:
kwargs['length'] = self.length
if self.columns:
kwargs['columns'] = self.columns
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.length is not None:
with_params.append('length = %d' % self.length)
if self.columns:
with_params.extend(
'col%d = %d' % (i, v)
for i, v in enumerate(self.columns, start=1)
)
return with_params
[документация]class BrinIndex(PostgresIndex):
suffix = 'brin'
def __init__(self, *expressions, autosummarize=None, pages_per_range=None, **kwargs):
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.autosummarize = autosummarize
self.pages_per_range = pages_per_range
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.autosummarize is not None:
kwargs['autosummarize'] = self.autosummarize
if self.pages_per_range is not None:
kwargs['pages_per_range'] = self.pages_per_range
return path, args, kwargs
def check_supported(self, schema_editor):
if self.autosummarize and not schema_editor.connection.features.has_brin_autosummarize:
raise NotSupportedError('BRIN option autosummarize requires PostgreSQL 10+.')
def get_with_params(self):
with_params = []
if self.autosummarize is not None:
with_params.append('autosummarize = %s' % ('on' if self.autosummarize else 'off'))
if self.pages_per_range is not None:
with_params.append('pages_per_range = %d' % self.pages_per_range)
return with_params
[документация]class BTreeIndex(PostgresIndex):
suffix = 'btree'
def __init__(self, *expressions, fillfactor=None, **kwargs):
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
[документация]class GinIndex(PostgresIndex):
suffix = 'gin'
def __init__(self, *expressions, fastupdate=None, gin_pending_list_limit=None, **kwargs):
self.fastupdate = fastupdate
self.gin_pending_list_limit = gin_pending_list_limit
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fastupdate is not None:
kwargs['fastupdate'] = self.fastupdate
if self.gin_pending_list_limit is not None:
kwargs['gin_pending_list_limit'] = self.gin_pending_list_limit
return path, args, kwargs
def get_with_params(self):
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 = %s' % ('on' if self.fastupdate else 'off'))
return with_params
[документация]class GistIndex(PostgresIndex):
suffix = 'gist'
def __init__(self, *expressions, buffering=None, fillfactor=None, **kwargs):
self.buffering = buffering
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.buffering is not None:
kwargs['buffering'] = self.buffering
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.buffering is not None:
with_params.append('buffering = %s' % ('on' if self.buffering else 'off'))
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
def check_supported(self, schema_editor):
if self.include and not schema_editor.connection.features.supports_covering_gist_indexes:
raise NotSupportedError('Covering GiST indexes requires PostgreSQL 12+.')
[документация]class HashIndex(PostgresIndex):
suffix = 'hash'
def __init__(self, *expressions, fillfactor=None, **kwargs):
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
[документация]class SpGistIndex(PostgresIndex):
suffix = 'spgist'
def __init__(self, *expressions, fillfactor=None, **kwargs):
self.fillfactor = fillfactor
super().__init__(*expressions, **kwargs)
def deconstruct(self):
path, args, kwargs = super().deconstruct()
if self.fillfactor is not None:
kwargs['fillfactor'] = self.fillfactor
return path, args, kwargs
def get_with_params(self):
with_params = []
if self.fillfactor is not None:
with_params.append('fillfactor = %d' % self.fillfactor)
return with_params
[документация]class OpClass(Func):
template = '%(expressions)s %(name)s'
def __init__(self, expression, name):
super().__init__(expression, name=name)