SELECT clock_timestamp(), pg_class.relname, pg_locks.locktype, pg_locks.database, pg_locks.relation, pg_locks.page, pg_locks.tuple, pg_locks.virtualtransaction, pg_locks.pid, pg_locks.mode, pg_locks.granted FROM
使用 PID 通过pg_locks连接pg_stat_activity允许您看到不仅锁，还有哪个数据库和查询涉及其中。提供的 SQL 查询将pg_locks与pg_stat_activity连接在一起，以显示当前锁的全面视图:SELECT pg_locks.pid, pg_stat_activity.datname, pg_locks.mode, pg_locks.relation, pg_locks.page, pg_locks...
SELECT*FROMpg_locks; 该视图包含了锁的类型、持有锁的事务、被锁定的对象等详细信息。 2. 监控锁等待:为了避免锁等待导致的性能问题,可以监控锁等待情况。通过查看pg_stat_activity视图,可以了解当前正在执行的事务以及它们是否处于等待锁的状态。例如: SELECT*FROMpg_stat_activityWHEREwaiting=true; 该查询会返回正...
select pg_database.datname, pg_database_size(pg_database.datname) AS size from pg_database; //查询所有数据库,及其所占空间大小 2. 查询存在锁的数据表 select a.locktype,a.database,a.pid,a.mode,a.relation,b.relname -- ,sa.* from pg_locks a join pg_class b on a.relation = b.o...
FROM pg_locks LEFT OUTER JOIN pg_class ON(pg_locks.relation=pg_class.oid)WHERE --donot show our view’s locks pid!=pg_backend_pid()AND -- no need to show self-vxid locks virtualtransaction IS DISTINCT FROM virtualxid -- granted is ordered earlier ...
使用 PID 通过pg_locks连接pg_stat_activity允许您看到不仅锁,还有哪个数据库和查询涉及其中。 提供的 SQL 查询将pg_locks与pg_stat_activity连接在一起,以显示当前锁的全面视图: SELECT pg_locks.pid, pg_stat_activity.datname, pg_locks.mode, pg_locks.relation, pg_locks.page, pg_locks.tuple FROM pg_...
PostgreSQL空闲事务诊断和读取pg_locks 是关于PostgreSQL数据库中空闲事务的诊断和读取pg_locks表的问题。 空闲事务是指在数据库中未被提交或回滚的事务。这些事务可能会导致数据库性能下降或资源浪费。因此,诊断和解决空闲事务是数据库管理中的重要任务。 在PostgreSQL中,可以使用以下步骤来诊断和解决空闲事务:...
LOCKTABLEproductsINEXCLUSIVEMODE; 1. 示例场景:在对商品表进行结构修改(如添加新列)时,为了防止其他事务干扰,需要锁定整个表。 意向锁(Intention Locks) 作用:用于表示事务对表中部分行(意向共享锁Intention Share Locks或意向排他锁Intention Exclusive Locks)加锁的意图,从而避免在获取行级锁时与其他事务的表级锁...
WAIT_EVENT_TYPE = 'Lock'; -- 通过pid解锁对应的ACTIVITY select PG_CANCEL_BACKEND(55195); select pg_terminate_backend(pid) SELECT pid, relname, transactionid, mode, granted FROM pg_locks JOIN pg_stat_user_tables ON pg_locks.relation = pg_stat_user_tables.relid 查询包含空间索引的表 select...
| => SELECT pg_backend_pid(); | pg_backend_pid | --- | 4746 | (1 row) 刚刚开始的事务持有什么锁?调查pg_locks: => SELECT locktype, relation::REGCLASS, virtualxid AS virtxid, transactionid AS xid, mode, granted FROM pg_locks WHERE...