Show info on postgres locks

pg_locks.sql

SELECT bl.pid                 AS blocked_pid,
       a.usename              AS blocked_user,
       ka.query               AS current_statement_in_blocking_process,
       now() - ka.query_start AS blocking_duration,
       kl.pid                 AS blocking_pid,
       ka.usename             AS blocking_user,
       a.query                AS blocked_statement,
       now() - a.query_start  AS blocked_duration
FROM  pg_catalog.pg_locks         bl
 JOIN pg_catalog.pg_stat_activity a  ON a.pid = bl.pid
 JOIN pg_catalog.pg_locks         kl ON kl.transactionid = bl.transactionid AND kl.pid != bl.pid
 JOIN pg_catalog.pg_stat_activity ka ON ka.pid = kl.pid
WHERE NOT bl.GRANTED;

# better blocking locks query
SET application_name='panoptes';
SELECT blocked_locks.pid     AS blocked_pid,
         blocked_activity.usename  AS blocked_user,
         blocking_locks.pid     AS blocking_pid,
         blocking_activity.usename AS blocking_user,
         blocked_activity.query    AS blocked_statement,
         blocking_activity.query   AS current_statement_in_blocking_process,
         blocked_activity.datname AS blocked_application
   FROM  pg_catalog.pg_locks         blocked_locks
    JOIN pg_catalog.pg_stat_activity blocked_activity  ON blocked_activity.pid = blocked_locks.pid
    JOIN pg_catalog.pg_locks         blocking_locks 
        ON blocking_locks.locktype = blocked_locks.locktype
        AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE
        AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation
        AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page
        AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple
        AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid
        AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid
        AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid
        AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid
        AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid
        AND blocking_locks.pid != blocked_locks.pid
 
    JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid
   WHERE NOT blocked_locks.GRANTED;

-- useful links for more detailed queries https://gist.github.com/rgreenjr/3637525

-- info on non-idle connections for the whole db
select pid, application_name, client_addr, waiting, state, now() - query_start as "runtime", query from pg_stat_activity
where state <> 'idle'
order by runtime

-- find info on active queries
select pid, application_name, client_addr, waiting, state, query from pg_stat_activity
where datname = 'panoptes' 
AND usename = 'panoptes'
and state = 'active'
--and pid = X;

-- kill a query
select pg_cancel_backend(pid)

-- kill a list of long running queries via a select call
SELECT pg_cancel_backend(pid) from pg_stat_activity
where state <> 'idle'
and application_name like 'puma%'
and now() - query_start > interval '30 second'
order by now() - query_start 
limit 5

select * from pg_stat_activity 

/* This lists queries causing locks. */
select pid, usename, pg_blocking_pids(pid) as blocked_by, query as blocked_query 
from pg_stat_activity 
where cardinality(pg_blocking_pids(pid)) > 0;