text: SET client_encoding TO 'UTF8';
  
  UPDATE weather SET temp_lo = temp_lo+1, temp_hi = temp_lo+15, prcp = DEFAULT
    WHERE city = 'San Francisco' AND date = '2003-07-03' RETURNING temp_lo,temp_hi,prcp;
  
  \set ON_ERROR_STOP ON
  
  SELECT * FROM (SELECT * FROM mytable FOR UPDATE) AS ss WHERE col1 = 5;
  
  BEGIN;
  SELECT * FROM mytable WHERE key = 1 FOR NO KEY UPDATE;
  SAVEPOINT s;
  UPDATE mytable SET col1=NULL WHERE key = 1;
  ROLLBACK TO s;
  
  