Oracle-查看sql运行状况
查看占io较大的正在运行的session
SELECT se.sid, se.serial#, pr.SPID, se.username, se.status, se.terminal, se.program, se.MODULE, se.sql_address, st.event, st. p1text, si.physical_reads, si.block_changes FROM v$session se, v$session_wait st, v$sess_io si, v$process pr WHERE st.sid = se.sid AND st. sid = si.sid AND se.PADDR = pr.ADDR AND se.sid > 6 AND st. wait_time = 0 AND st.event NOT LIKE '%SQL%' ORDER BY physical_reads DESC;
查找前十条性能差的sql
SELECT * FROM (select PARSING_USER_ID, EXECUTIONS, SORTS, COMMAND_TYPE, DISK_READS, sql_text FROM v$sqlarea order BY disk_reads DESC) where ROWNUM < 10;
从V$SQLAREA中查询最占用资源的查询
select b.username username,a.disk_reads reads,a.BUFFER_GETS as buffer, a.executions exec,a.disk_reads/decode(a.executions,0,1,a.executions) rds_exec_ratio, a.sql_text Statement from v$sqlarea a,dba_users b where a.parsing_user_id=b.user_id and a.disk_reads > 100000 order by a.disk_reads desc;
列出使用频率最高的5个查询
select sql_text,executions from (select sql_text,executions, rank() over (order by executions desc) exec_rank from v$sql) where exec_rank <=5;
消耗磁盘读取最多的sql top5
select disk_reads,sql_text from (select sql_text,disk_reads, dense_rank() over (order by disk_reads desc) disk_reads_rank from v$sql) where disk_reads_rank <=5;
找出需要大量缓冲读取(逻辑读)操作的查询
select buffer_gets,sql_text from (select sql_text,buffer_gets, dense_rank() over (order by buffer_gets desc) buffer_gets_rank from v$sql) where buffer_gets_rank<=5;
人们永远没有足够的时间把它做好,但永远有足够的时间重新来过。 可是,因为并不是总有机会重做一遍,你必须做得更好,换句话说, 人们永远没有足够的时间去考虑到底是不是想要它,但永远有足够的时间去为之后悔。 ★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★★ 浅掘千口井,不如深挖一口井!当知识支撑不了野心时,那就静下心来学习吧!运维技术交流QQ群:618354452
个人微信公众号,定期发布技术文章和运维感悟。欢迎大家关注交流。