如何查看PostgreSQL正在执行的SQL

SELECT 

procpid, 

start, 

now() - start AS lap, 

current_query 

FROM 

(SELECT 

backendid, 

pg_stat_get_backend_pid(S.backendid) AS procpid, 

pg_stat_get_backend_activity_start(S.backendid) AS start, 

pg_stat_get_backend_activity(S.backendid) AS current_query 

FROM 

(SELECT pg_stat_get_backend_idset() AS backendid) AS S 

) AS S 

WHERE 

current_query <> '<IDLE>' 

ORDER BY 

lap DESC;