22 lines
813 B
PL/PgSQL
Executable File
22 lines
813 B
PL/PgSQL
Executable File
-- Add a postgis GEOMETRY column to the way table for the purpose of indexing the location of the way.
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-- This will contain a bounding box surrounding the extremities of the way.
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SELECT AddGeometryColumn('ways', 'bbox', 4326, 'GEOMETRY', 2);
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-- Add an index to the bbox column.
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CREATE INDEX idx_ways_bbox ON ways USING gist (bbox);
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-- Cluster table by geographical location.
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CLUSTER ways USING idx_ways_bbox;
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-- Create an aggregate function that always returns the first non-NULL item. This is required for bbox queries.
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CREATE OR REPLACE FUNCTION first_agg (anyelement, anyelement)
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RETURNS anyelement AS $$
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SELECT CASE WHEN $1 IS NULL THEN $2 ELSE $1 END;
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$$ LANGUAGE SQL STABLE;
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CREATE AGGREGATE first (
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sfunc = first_agg,
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basetype = anyelement,
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stype = anyelement
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);
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