text: -- +++
  -- parent: 1000000002
  -- +++
  
  BEGIN;
  
  DELETE FROM series_points; -- affects dev environments only, others never had data in this table.
  ALTER TABLE series_points ALTER COLUMN series_id TYPE text;
  ALTER TABLE series_points ALTER COLUMN series_id SET NOT NULL;
  
  -- Give series_id a btree index since we'll be filtering on it very frequently.
  CREATE INDEX series_points_series_id_btree ON series_points USING btree (series_id);
  
  COMMIT;
  