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Simplified PostGIS index creation 

Less special-casing and code more in line with 'normal' index creation.
This commit is contained in:
Claude Paroz 2016-09-17 17:51:13 +02:00
parent 9715b99f91
commit 35e649b197
1 changed files with 23 additions and 51 deletions
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74
django/contrib/gis/db/backends/postgis/schema.py
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@ -6,61 +6,33 @@ class PostGISSchemaEditor(DatabaseSchemaEditor):
geom_index_ops_nd = 'GIST_GEOMETRY_OPS_ND'
rast_index_wrapper = 'ST_ConvexHull(%s)'
sql_add_spatial_index = "CREATE INDEX %(index)s ON %(table)s USING %(index_type)s (%(column)s %(ops)s)"
def __init__(self, *args, **kwargs):
super(PostGISSchemaEditor, self).__init__(*args, **kwargs)
self.geometry_sql = []
def geo_quote_name(self, name):
return self.connection.ops.geo_quote_name(name)
def column_sql(self, model, field, include_default=False):
from django.contrib.gis.db.models.fields import BaseSpatialField
if not isinstance(field, BaseSpatialField):
return super(PostGISSchemaEditor, self).column_sql(model, field, include_default)
def _field_should_be_indexed(self, model, field):
if getattr(field, 'spatial_index', False):
return True
return super(PostGISSchemaEditor, self)._field_should_be_indexed(model, field)
column_sql = super(PostGISSchemaEditor, self).column_sql(model, field, include_default)
def _create_index_sql(self, model, fields, suffix="", sql=None):
if len(fields) != 1 or not hasattr(fields[0], 'geodetic'):
return super(PostGISSchemaEditor, self)._create_index_sql(model, fields, suffix=suffix, sql=sql)
if field.spatial_index:
# Spatial indexes created the same way for both Geometry and
# Geography columns.
field_column = self.quote_name(field.column)
if field.geom_type == 'RASTER':
# For raster fields, wrap index creation SQL statement with ST_ConvexHull.
# Indexes on raster columns are based on the convex hull of the raster.
field_column = self.rast_index_wrapper % field_column
index_ops = ''
elif field.geography:
index_ops = ''
else:
# Use either "nd" ops which are fast on multidimensional cases
# or just plain gist index for the 2d case.
if field.dim > 2:
index_ops = self.geom_index_ops_nd
else:
index_ops = ''
self.geometry_sql.append(
self.sql_add_spatial_index % {
"index": self.quote_name('%s_%s_id' % (model._meta.db_table, field.column)),
"table": self.quote_name(model._meta.db_table),
"column": field_column,
"index_type": self.geom_index_type,
"ops": index_ops,
}
)
return column_sql
field = fields[0]
field_column = self.quote_name(field.column)
def create_model(self, model):
super(PostGISSchemaEditor, self).create_model(model)
# Create geometry columns
for sql in self.geometry_sql:
self.execute(sql)
self.geometry_sql = []
if field.geom_type == 'RASTER':
# For raster fields, wrap index creation SQL statement with ST_ConvexHull.
# Indexes on raster columns are based on the convex hull of the raster.
field_column = self.rast_index_wrapper % field_column
elif field.dim > 2 and not field.geography:
# Use "nd" ops which are fast on multidimensional cases
field_column = "%s %s" % (field_column, self.geom_index_ops_nd)
def add_field(self, model, field):
super(PostGISSchemaEditor, self).add_field(model, field)
# Create geometry columns
for sql in self.geometry_sql:
self.execute(sql)
self.geometry_sql = []
return self.sql_create_index % {
"name": self.quote_name('%s_%s_id' % (model._meta.db_table, field.column)),
"table": self.quote_name(model._meta.db_table),
"using": "USING %s" % self.geom_index_type,
"columns": field_column,
"extra": '',
}