Wait eventDefinition Client:ClientRead This event occurs when Aurora PostgreSQL is waiting to receive data from the client. Client:ClientWrite This event occurs when Aurora PostgreSQL is waiting to write data to the client. CPU This event occurs when a thread is active in CPU or is waiting for...
Wait Event TypeWait Event NameDescription LWLock ShmemIndexLock Waiting to find or allocate space in shared memory. OidGenLock Waiting to allocate or assign an OID. XidGenLock Waiting to allocate or assign a transaction id. ProcArrayLock Waiting to get a snapshot or clearing a transaction id ...
This wait event occurs when operations write to the temporary files. For more information, see IO:BufFileRead and IO:BufFileWrite. IO:ControlFileRead A process is waiting for a read from the pg_control file. IO:ControlFileSync A process is waiting for the pg_control file to reach durable...
This wait event is experienced whenever the database needs to open a file. Wait time is recorded beginning just prior to when the open request is issued until the time the request is returned, having Oracle 数据库 OraclecursorpinSwaitonX等待事件说明 这个等待事件也算一个常见的等待事件。 在...
wait_event|ClientRead state|idleintransactionbackend_xid|1286297004backend_xmin|query|truncatea;backend_type|client backend 如果当前状态没有找到具体是哪条SQL导致的锁,则需要从审计日志中查找(开启log_statements='all')。重点关注wait_event_type和state字段。这里说明该holder执行完事务后处于空闲状态,正等待客...
postgresql等待事件之wait_event为空null解析 查看某个语句的当前等待事件可以查询pg_stat_activity表(类似于Oracle的v$session),如下所示: select wait_event_type,wait_event,state,query,a.* from pg_stat_activity a where query like 'insert%'; 1....
WaitEventSet的等待超时如何实现?我们了解到,它和epoll有关,首先先了解下epoll_wait这个函数:int epoll_wait( int epfd,//epoll_create函数返回的epoll实例的句柄 struct epoll_event * events, //出参。Epoll将发生的事件集合从内核复制到该数组 int maxevents,...
CDW PG作为分布式数据库，执行query需要多个CN和DN交互运行，对于复杂查询，甚至会出现多层调用的情况。CN...
select pid,now()-query_start as "执行时间",wait_event_type,wait_event,query from pg_stat_activity; 上面两个SQL执行的效果是一致的,直接查看整个视图信息会较全,但是比较多,可使用第二个视图,其中,wait_event wait_event_type 字段代表等待事件。不同的等待事件代表不同的含义。
,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 ...