1/5用友股份-LE支持服务业务本部技术方案--《删除dba_recyclebin表》建立日期：2013-10-20修改日期：xxxx-xx-xx文档属性：客户文控编号：LE-DY-JS-2013-01172/5文档控制创建记录适用范围审阅人日期审阅签字所属部门发布范围发布人姓名所属部门发布时间内部员工伙伴客户日期作者所属部门邮件地址版本2013-10-20白晓宇技术支持部V1.0版本领域模块备注3/5目录删除dba_recyclebin表.............................................................................................44/5删除dba_recyclebin表发现一个语句消耗资源很大EXPLAINPLANFORselectround((1-sumfree/sumtotal)*100,2)from(selectsum(bytes)sumtotalfromdba_data_files)a,(selectsum(bytes)sumfreefromdba_free_space)b看到recyclebin中有很多的表，使用下面的purgedba_recyclebin命令删除，遇到下面的等待事件，很慢查看资料TherdbmsipcreplyOraclemetriceventisusedtowaitforareplyfromoneofthebackgroundprocesses.SteveAdamsnoteson"rdbmsipcreply":"YourwritecompletewaitsandrdbmsipcreplywaitsindicatetheeitherDBWn'swritebatchistoobig,oryouarecheckpointingtoointensively.Makesurethatdb_filesisnotmuchhigherthanthenumberofdatafilesthatyouactuallyhave.Ifyouareusingincrementalcheckpoints(db_block_max_dirty_target)don'tbetooambitious."OnOracleMOSCForums,auserwashavingtroublewithaslowdatabase,andwasconcernedwiththerdbmsipcreplywasthehighestwaitevent.Areplierhelpedresolvetheissuebyinfromingtheuserthattheyshould:1.MakesureyourparfilehasthelineCOMMIT=NOtherwise,Oraclewillperformacommitaftereachrowisinserted,andthatmaybethecauseofyourproblems.2.Enlargethesizeofyourredotillyouareonlyperforming1logswitchevery10-20minutes.3.'RDBMSIPCREPLY'issharedmemorysegmentspassingmessages(usuallyflags)backandforth.Thisisnothingtogetworriedabout,andmostpeople5/5considerittobeanidlewaitevent.4.Runastatspakreportfor15minutesduringtheimport,andthatwillshowwhereyourproblemsreallyare,likehotblocksetc.但是跟我的问题也不是很相关的啊。很慢很慢的才删除完了的
