SELECT DISTINCTr.cache#, r.parameter name, r.TYPE, r.subordinate#, r.gets FROMv$rowcache r ORDER BY1, 4,5; 查看row cache objects具体包含的内容。 SET PAGES 1000 COLUMN cache# FORMAT 99999 COLUMN nameFORMAT a33 COLUMN latch# FORMAT 999999 SELECTDISTINCTs.kqrstcln latch#, r.cache#, r.p...
查看row cache 中的对象 column cache# format 99999 column name format a33 column latch# format 999999 select distinct s.kqrstcln latch#,r.cache#,r.parameter name, r.type, r.subordinate#,r.gets from v$rowcache r,x$kqrst s where r.cache#=s.kqrstcid order by 1,4,5; select t.paramet...
然后再去查询等待事件: select inst_id,event,count(1) from gv$session where wait_class#<> 6 group by inst_id,event order by 1,3; 发现已经没有latch: row cache objects 这个等待事件了... 估计sid=300的session退出了.
查看等待时间,查看产生的地址争用 select p1 ,p1raw,p2 from v$session_wait where event='latch: row cache objects'; 查看该使用地址块的,misses丢失率 select * from v$latch_children where name like '%row cache objects%' 查看row cache 中的对象 column cache# format 99999 column name format a33 c...
通过如下分析是由于故障时段有大量硬解析,硬解析需要去获取数据字典资源,这需要获得latch,若硬解析量太大,会造成严重的latch争用,占用非常多的资源,导致CPU使用过高,从而表现出数据库ROW CACHE OBJECT等待事件,最终导致数据库系统缓慢。 根据分析,我方有如下2点建议: ...
application objects, especially indexes, may decrease Row Cache locks. Review and amend database logical design. For example, try to decrease the number of indexes on tables with frequent inserts.
application objects, especially indexes, may decrease Row Cache locks. Review and amend database logical design. For example, try to decrease the number of indexes on tables with frequent inserts.
Get the P1 value of event 'latch: row cache objects', convert it to Hex value, and below query shows the latch is on dc_objects: SQL> select la.addr laaddr,dc.kqrstcid CACHE#, dc.kqrsttxt PARAMETER, 2 decode(dc.kqrsttyp, 1,'PARENT','SUBORDINATE') type, ...
latch: row cache objects等待事件分析 AWR Report shows contention for 'row cache objects' as the top wait: Top 5 Timed Foreground Events Event Waits Time(s) Avg wait (ms) DB time Wait Class latch: row cache objects 58,291,873 130,700 2 63.18 Concurrency...
High Row Cache contention on dc_rollback_segments in Data Guard Active Standby (ADG) manifested with wait events "latch: row cache objects" or "Child row cache objects". This fix provides a latchless enhancement for alleviating "row cache objects" latch contention ...