版权声明：本文为博主原创文章，转载请标明出处。 https://blog.csdn.net/ctypyb2002/article/details/83752735
session 阻塞的监控在数据库是重要的监控指标之一。
9.6
with recursive tmp_lock as (
select distinct
--w.mode w_mode,w.page w_page,
--w.tuple w_tuple,w.xact_start w_xact_start,w.query_start w_query_start,
--now()-w.query_start w_locktime,w.query w_query
w.pid as id,--w_pid,
r.pid as parentid--r_pid,
--r.locktype,r.mode r_mode,r.usename r_user,r.datname r_db,
--r.relation::regclass,
--r.page r_page,r.tuple r_tuple,r.xact_start r_xact_start,
--r.query_start r_query_start,
--now()-r.query_start r_locktime,r.query r_query,
from (
select a.mode,a.locktype,a.database,
a.relation,a.page,a.tuple,a.classid,
a.objid,a.objsubid,a.pid,a.virtualtransaction,a.virtualxid,
a.transactionid,
b.query as query,
b.xact_start,b.query_start,b.usename,b.datname
from pg_locks a,
pg_stat_activity b
where a.pid=b.pid
and not a.granted
) w,
(
select a.mode,a.locktype,a.database,
a.relation,a.page,a.tuple,a.classid,
a.objid,a.objsubid,a.pid,a.virtualtransaction,a.virtualxid,
a.transactionid,
b.query as query,
b.xact_start,b.query_start,b.usename,b.datname
from pg_locks a,
pg_stat_activity b -- select pg_typeof(pid) from pg_stat_activity
where a.pid=b.pid
and a.granted
) r
where
r.locktype is not distinct from w.locktype and
r.database is not distinct from w.database and
r.relation is not distinct from w.relation and
r.page is not distinct from w.page and
r.tuple is not distinct from w.tuple and
r.classid is not distinct from w.classid and
r.objid is not distinct from w.objid and
r.objsubid is not distinct from w.objsubid and
r.transactionid is not distinct from w.transactionid and
r.pid <> w.pid
),tmp0 as (
select *
from tmp_lock tl
union all
--查找root，同一时刻可能有多个root
select t1.parentid,0::int4
from tmp_lock t1
where 1=1
and t1.parentid not in (select id from tmp_lock)
),tmp3 (pathid,depth,id,parentid) as (
--对过滤出的机构向下递归，构成tree
SELECT array[id]::text[] as pathid,1 as depth,id,parentid
FROM tmp0
where 1=1
and parentid=0
union
SELECT t0.pathid||array[t1.id]::text[] as pathid,t0.depth+1 as depth,t1.id,t1.parentid
FROM tmp0 t1,
tmp3 t0
where 1=1
and t1.parentid=t0.id
)
select distinct
'/'||array_to_string(a0.pathid,'/') as pathid,
a0.depth,
a0.id,a0.parentid,lpad(a0.id::text, 2*a0.depth-1+length(a0.id::text),' ') as tree_id,
case when a0.depth =1 then 'select pg_terminate_backend('|| a0.id || ');' else null end as term_pid,
case when a0.depth =1 then 'select cancel_backend('|| a0.id || ');' else null end as cancel_pid
,a2.datname,a2.usename,a2.application_name,a2.client_addr,a2.wait_event_type,a2.wait_event,a2.state
--,a2.backend_start,a2.xact_start,a2.query_start
from tmp3 a0
left outer join (select distinct '/'||id||'/' as prefix_id,id
from tmp0
where 1=1 ) a1
on position( a1.prefix_id in '/'||array_to_string(a0.pathid,'/')||'/' ) >0
left outer join pg_stat_activity a2 -- select * from pg_stat_activity
on a0.id = a2.pid
order by '/'||array_to_string(a0.pathid,'/'),a0.depth
;
pathid | depth | id | parentid | tree_id | datname | usename | application_name | client_addr | wait_event_type | wait_event | state | backend_start | xact_start | query_start
--------------------+-------+-------+----------+------------+----------+----------+------------------+-------------+-----------------+---------------+---------------------+-------------------------------+-------------------------------+-------------------------------
/10180 | 1 | 10180 | 0 | 10180 | postgres | postgres | psql | | | | idle in transaction | 2018-11-05 15:25:56.473886+08 | 2018-11-05 15:26:12.529745+08 | 2018-11-05 16:30:50.347912+08
/10180/10197 | 2 | 10197 | 10180 | 10197 | postgres | postgres | psql | | Lock | transactionid | active | 2018-11-05 15:26:02.12397+08 | 2018-11-05 15:26:30.767745+08 | 2018-11-05 15:26:30.767745+08
/10180/10197/10508 | 3 | 10508 | 10197 | 10508 | postgres | postgres | psql | | Lock | tuple | active | 2018-11-05 16:38:02.858333+08 | 2018-11-05 16:38:19.514655+08 | 2018-11-05 16:38:19.514655+08
/9782 | 1 | 9782 | 0 | 9782 | postgres | postgres | psql | | | | idle in transaction | 2018-11-05 15:05:04.656155+08 | 2018-11-05 15:11:45.731423+08 | 2018-11-05 15:46:24.559188+08
/9782/10026 | 2 | 10026 | 9782 | 10026 | postgres | postgres | psql | | Lock | transactionid | active | 2018-11-05 15:24:02.389744+08 | 2018-11-05 15:50:16.546751+08 | 2018-11-05 15:50:38.428968+08
/9782/10026/9918 | 3 | 9918 | 10026 | 9918 | postgres | postgres | psql | | Lock | tuple | active | 2018-11-05 15:11:31.394268+08 | 2018-11-05 15:50:19.964021+08 | 2018-11-05 15:50:45.080284+08
(6 rows)