Performantly update table with 2 million rows with Postgres/PostGIS

Question

I have two tables:

• properties (geo_point POINT, locality_id INTEGER, neighborhood_id INTEGER, id UUID)
• places_temp (id INTEGER, poly GEOMETRY, placetype TEXT)

Note: all columns in places_temp are indexed.

properties has ~2 million rows and I would like to:

• update locality_id and neighborhood_id for each row in properties with the id from places_temp where properties.geo_point is contained by a polygon in places_temp.poly

Whatever I do it just seems to hang for hours within which time I don't know if it's working, the connection is lost, etc.

Any thoughts on how to do this performantly?

My query:

  -- drop indexes on locality_id and neighborhood_id to speed up update
  DROP INDEX IF EXISTS idx_properties_locality_id;
  DROP INDEX IF EXISTS idx_properties_neighborhood_id;
  -- for each property find the locality and neighborhood
  UPDATE
    properties
  SET
    locality_id = (
      SELECT
        id
      FROM
        places_temp
      WHERE
        placetype = 'locality'
        -- check if geo_point is contained by polygon. geo_point is stored as SRID 26910 so must be
        -- transformed first
        AND st_intersects (st_transform (geo_point, 4326), poly)
      LIMIT 1),
  neighborhood_id = (
    SELECT
      id
    FROM
      places_temp
    WHERE
      placetype = 'neighbourhood'
      -- check if geo_point is contained by polygon. geo_point is stored as SRID 26910 so must be
      -- transformed first
      AND st_intersects (st_transform (geo_point, 4326), poly)
    LIMIT 1);
  -- Add indexes back after update
  CREATE INDEX IF NOT EXISTS idx_properties_locality_id ON properties (locality_id);
  CREATE INDEX IF NOT EXISTS idx_properties_neighborhood_id ON properties (neighborhood_id);

Answer 1

CREATE INDEX properties_point_idx ON properties USING gist (geo_point);
CREATE INDEX places_temp_poly_idx ON places_temp USING gist (poly);

UPDATE properties p
SET locality_id = x.id
FROM ( SELECT *
        , row_number() OVER () rn
        FROM places_temp t 
        WHERE t.placetype = 'locality'
        AND st_intersects (st_transform (p.geo_point, 4326), t.poly)
        )x
WHERE x.rn = 1
      ;

And similar for the other field (you could combine them into one query)

Answer 2

Try this

        UPDATE
      properties
   SET
    locality_id =t.id, neighbourhood_id
    =t.id
    From(
    SELECT
    id
    FROM
    places_temp
  WHERE
    placetype in ('locality',  
   'neighbourhood') 
    AND st_intersects (st_transform 
   (geo_point, 4326), poly)
  LIMIT 1)) t