Change all timestamp to timestamptz in schema

gistfile1.txt

CREATE OR REPLACE FUNCTION change_tz() RETURNS integer AS $$
DECLARE
    query varchar;
    result integer := 0;
    rel RECORD;
    col RECORD;
BEGIN
    FOR rel IN SELECT DISTINCT table_name FROM information_schema.columns WHERE table_schema =  'public' AND data_type = 'timestamp without time zone' AND table_name not like 'databasechangelog%' LOOP
      query := 'ALTER TABLE ' || quote_ident(rel.table_name) || ' SET WITHOUT CLUSTER'; -- NOOP, makes combining easier

      FOR col IN SELECT column_name FROM information_schema.columns WHERE table_schema =  'public' AND data_type = 'timestamp without time zone' AND table_name = rel.table_name LOOP
          -- RAISE NOTICE 'Table: %, Column: %', quote_ident(entry.table_name), quote_ident(entry.column_name);
          query := query || ', ALTER COLUMN ' || quote_ident(col.column_name) || ' TYPE timestamp with time zone USING ' || quote_ident(col.column_name) || ' AT TIME ZONE ''Europe/Berlin''';
      END LOOP;
      RAISE NOTICE '%', query;
      EXECUTE query;

    END LOOP;
    result := result + 1;
    RETURN result;
END;
$$ LANGUAGE plpgsql;