psql中使用\watch反复查看语句执行结果

test=> \c test a
You are now connected to database "test" as user "a".
test=> select * from a.test;
 id 
----
  1
(1 row)


test=> select * from a.test; \watch 1      -----单位为秒
 id 
----
  1
(1 row)


Wed 08 Feb 2017 09:57:04 AM CST (every 1s)


 id 
----
  1
(1 row)


Wed 08 Feb 2017 09:57:05 AM CST (every 1s)


 id 
----
  1
(1 row)


Wed 08 Feb 2017 09:57:06 AM CST (every 1s)


 id 
----
  1
(1 row)


Wed 08 Feb 2017 09:57:07 AM CST (every 1s)


 id 
----
  1
(1 row)