13518219792
实例级别的监控，一直开启并且低开销：
建立基础表：
create table sys.sesstat_history tablespace EOL as SELECT c.username, c.osuser, a.sid, c.serial#, c.paddr, c.process, c.logon_time, a.statistic#, b.name, a.value, SYSDATE AS logoff_timestamp FROM v$sesstat a, v$statname b, v$session c WHERE 1 = 2 create table sys.session_event_history tablespace EOL as SELECT b.sid, b.SERIAL#, b.username, b.osuser, b.paddr, b.process, b.logon_time, b.type, a.event, a.total_waits, a.total_timeouts, a.time_waited, a.average_wait, a.max_wait, SYSDATE AS logoff_timestamp FROM v$session_event a, v$session b WHERE 1 = 2创建触发器：
CREATE OR REPLACE TRIGGER sys.logoff_trig BEFORE logoff ON DATABASE DECLARE logoff_sid PLS_INTEGER; logoff_time DATE := SYSDATE; BEGIN SELECT sid INTO logoff_sid FROM v$mystat WHERE rownum < 2; INSERT INTO sys.session_event_history (sid, serial#, username, osuser, paddr, process, logon_time, TYPE, event, total_waits, total_timeouts, time_waited, average_wait, max_wait, logoff_timestamp) SELECT b.sid, b.serial#, b.username, b.osuser, b.paddr, b.process, b.logon_time, b.type, a.event, a.total_waits, a.total_timeouts, a.time_waited, a.average_wait, a.max_wait, SYSDATE AS logoff_timestamp FROM v$session_event a, v$session b WHERE a.sid = b.sid AND b.username = login_user AND b.sid = logoff_sid; INSERT INTO sys.sesstat_history (username, osuser, sid, serial#, paddr, process, logon_time, statistic#, NAME, VALUE, logoff_timestamp) SELECT c.username, c.osuser, a.sid, c.serial#, c.paddr, c.process, c.logon_time, a.statistic#, b.name, a.value, logoff_time FROM v$sesstat a, v$statname b, v$session c WHERE a.statistic# = b.statistic# AND a.sid = c.sid AND b.name IN ('CPU used where call started', 'CPU used by this session', 'recursive cpu usage', 'parse time cpu') AND c.sid = logoff_sid AND c.username = login_user; END;查询消耗CPU的等待事件排名：
SQL> SELECT * FROM (SELECT a.sid, a.serial#, a.event, a.total_waits FROM session_event_history a ORDER BY a.time_waited DESC) WHERE rownum < 100; 2 3 4 5 SID SERIAL# EVENT TOTAL_WAITS ---------- ---------- ------------------------------------------------------------ ----------- 1858 8391 SQL*Net message from client 147692 1437 52565 SQL*Net message from client 34305 584 52801 SQL*Net message from client 85105 585 40229 SQL*Net message from client 163331 874 3263 SQL*Net message from client 77519 1285 21797 SQL*Net message from client 19041 861 25015 SQL*Net message from client 194 726 9275 SQL*Net message from client 66724 1717 1935 SQL*Net message from client 92394 1014 883 SQL*Net message from client 34455 21 10841 SQL*Net message from client 28685另外有需要云服务器可以了解下创新互联cdcxhl.cn，海内外云服务器15元起步，三天无理由+7*72小时售后在线，公司持有idc许可证，提供“云服务器、裸金属服务器、高防服务器、香港服务器、美国服务器、虚拟主机、免备案服务器”等云主机租用服务以及企业上云的综合解决方案，具有“安全稳定、简单易用、服务可用性高、性价比高”等特点与优势，专为企业上云打造定制，能够满足用户丰富、多元化的应用场景需求。
