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