本节介绍了在pg_locks和pg_stat_activity两张基表基础上创建的视图. 显示阻塞信息的视图: ``` CREATE OR REPLACE VIEW vw_lockinfo AS 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 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; [local]:5432 pg12@testdb=# CREATE OR REPLACE VIEW vw_lockinfo pg12@testdb-# AS pg12@testdb-# SELECT blocked_locks.pid AS blocked_pid, pg12@testdb-# blocked_activity.usename AS blocked_user, pg12@testdb-# blocking_locks.pid AS blocking_pid, pg12@testdb-# blocking_activity.usename AS blocking_user, pg12@testdb-# blocked_activity.query AS blocked_statement, pg12@testdb-# blocking_activity.query AS current_statement_in_blocking_process pg12@testdb-# FROM pg_catalog.pg_locks blocked_locks pg12@testdb-# JOIN pg_catalog.pg_stat_activity blocked_activity ON blocked_activity.pid = blocked_locks.pid pg12@testdb-# JOIN pg_catalog.pg_locks blocking_locks pg12@testdb-# ON blocking_locks.locktype = blocked_locks.locktype pg12@testdb-# AND blocking_locks.DATABASE IS NOT DISTINCT FROM blocked_locks.DATABASE pg12@testdb-# AND blocking_locks.relation IS NOT DISTINCT FROM blocked_locks.relation pg12@testdb-# AND blocking_locks.page IS NOT DISTINCT FROM blocked_locks.page pg12@testdb-# AND blocking_locks.tuple IS NOT DISTINCT FROM blocked_locks.tuple pg12@testdb-# AND blocking_locks.virtualxid IS NOT DISTINCT FROM blocked_locks.virtualxid pg12@testdb-# AND blocking_locks.transactionid IS NOT DISTINCT FROM blocked_locks.transactionid pg12@testdb-# AND blocking_locks.classid IS NOT DISTINCT FROM blocked_locks.classid pg12@testdb-# AND blocking_locks.objid IS NOT DISTINCT FROM blocked_locks.objid pg12@testdb-# AND blocking_locks.objsubid IS NOT DISTINCT FROM blocked_locks.objsubid pg12@testdb-# AND blocking_locks.pid != blocked_locks.pid pg12@testdb-# pg12@testdb-# JOIN pg_catalog.pg_stat_activity blocking_activity ON blocking_activity.pid = blocking_locks.pid pg12@testdb-# WHERE NOT blocked_locks.GRANTED; CREATE VIEW Time: 131.424 ms [local]:5432 pg12@testdb=# select * from vw_lockinfo; -[ RECORD 1 ]-------------------------+--------------------------------------------------------------------------------------------------------------------------------------------------------------------- blocked_pid | 2184 blocked_user | pg12 blocking_pid | 2863 blocking_user | pg12 blocked_statement | update t_lock set id = 1000 where id = 1; current_statement_in_blocking_process | select pid,locktype,relation::regclass,mode,page,tuple,virtualxid,transactionid,virtualtransaction,granted,fastpath from pg_locks where relation='t_lock'::regclass; Time: 21.032 ms ``` 显示带有时间属性的locks ``` CREATE OR REPLACE VIEW vw_lockinfo_time AS SELECT a.datname, l.relation::regclass, l.transactionid, l.mode, l.GRANTED, a.usename, a.query, a.query_start, age(now(), a.query_start) AS "age", a.pid FROM pg_stat_activity a JOIN pg_locks l ON l.pid = a.pid ORDER BY a.query_start; [local]:5432 pg12@testdb=# CREATE OR REPLACE VIEW vw_lockinfo_time pg12@testdb-# AS pg12@testdb-# SELECT a.datname, pg12@testdb-# l.relation::regclass, pg12@testdb-# l.transactionid, pg12@testdb-# l.mode, pg12@testdb-# l.GRANTED, pg12@testdb-# a.usename, pg12@testdb-# a.query, pg12@testdb-# a.query_start, pg12@testdb-# age(now(), a.query_start) AS "age", pg12@testdb-# a.pid pg12@testdb-# FROM pg_stat_activity a pg12@testdb-# JOIN pg_locks l ON l.pid = a.pid pg12@testdb-# ORDER BY a.query_start; CREATE VIEW Time: 17.799 ms [local]:5432 pg12@testdb=# select * from vw_lockinfo_time; -[ RECORD 1 ]-+-------------------------------------------------------------------------------- ------------------------------------------------------------------------------------- datname | testdb relation | t_lock transactionid | mode | RowExclusiveLock granted | t usename | pg12 query | select pid,locktype,relation::regclass,mode,page,tuple,virtualxid,transactionid ,virtualtransaction,granted,fastpath from pg_locks where relation='t_lock'::regclass; query_start | 2019-08-13 15:32:23.139886+08 age | 00:11:29.095421 pid | 2863 ... ``` **参考资料** [Lock Monitoring](https://wiki.postgresql.org/wiki/Lock_Monitoring)