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 pg_locks JOIN pg_class ON pg_locks.relation = pg_class.oid WHERE relnam...
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...
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 * FROM pg_locks;-- Only relevant parts of output locktype | database | relation | page | tuple | virtualxid | transactionid | classid | objid | objsubid | virtualtransaction | pid | mode | granted |fastpath---+---+---+---+---+---+---+---+---+---+---+---...
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_...
select a.locktype,a.database,a.pid,a.mode,a.relation,b.relname from pg_locks a join pg_class b on a.relation = b.oid where upper(b.relname) = 'TABLE_NAME'; 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.
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...
SELECT pg_cancel_backend('死锁那条数据的procpid值 '); 结果:运行完后,再次更新这个表,sql顺利执行。 如果pg_stat_activity 没有记录,则查询pg_locks是否有这个对象的锁 selectoid,relnamefrompg_classwhererelname='table name';selectlocktype,pid,relation,mode,granted,*frompg_lockswhererelation='上面查询出...
blocking_activity.queryAScurrent_statement_in_blocking_processFROMpg_catalog.pg_locks blocked_locksJOINpg_catalog.pg_stat_activity blocked_activityONblocked_activity.pid=blocked_locks.pidJOINpg_catalog.pg_locks blocking_locksONblocking_locks.locktype=blocked_locks.locktypeANDblocking_locks.DATABASEISNOTDIS...