postgres - 列出耗时进程，干掉进程，以及$1的使用 list process list , stop process

refer to:
https://www.sqlprostudio.com/blog/8-killing-cancelling-a-long-running-postgres-query

列出进程：

https://josuamarcelc.com/show-full-processlist-in-postgresql/

SELECT user, pid, client_addr, query, query_start, NOW() - query_start AS elapsed
FROM pg_stat_activity
WHERE query != ''
-- AND EXTRACT(EPOCH FROM (NOW() - query_start)) > 1
ORDER BY elapsed DESC;

干掉进程：

Option #1 (graceful):

SELECT pg_cancel_backend(<PID>);

Option #2 (forceful):

SELECT pg_terminate_backend(<PID>);

列出index:

\d your_table_name