???????????????top 5??????????????????????????????top

????sql:1.?????CPU??(???IO?????)2.???1???????I/O??(????IO?????)3.??д??????????(Execution?????????)4.??????????(Elapse time??????)

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????control file sequential read

????control file single write ???????????????/???????????д????????????I/O ??????????????????????????????????????????鵥????????????????λ????????I/O ?????

????control file parallel write????server ??????????п?????????????????????????????????????????????????????????????????????????????I/O ???????????

??????XXX????????????????????AWR?????е?????????statspack??????￡????????λ???? SQL ??????ò??oracle????????????????????????????????????????????????DBA???????

?????????Щ?????????????????????????????????????涼???????????????????·???????????????????????????????????????????????????????????????????

??????????????汨?????壬Statistic?????????????????????????????????????????????????????????????top5?????????????????(Wait Events)??Oracle?б????????????Oracle ????????????Oracle ?????????????????????????????????????????????????????????ж?????????Σ???????ο?oracle?????????????????????XXX?????е??????????????????????????λ????????? "?????????" ????????????????????????????log file sync: ????????????????????????????? ???LGWR (Log Writer)??session ??????????redo buffer д??????????С?log file sync ??????????????????(Oracle ???дredo log file ???commit ?????????????)?????????????????????????????????????????????????????????????????????????????????????

????SQL?????????????????????SQL ordered by Elapsed time????sql?????????????????SQL ordered by CPU???????????CPU????SQL ordered by Gets???sql??????????????SQL ordered by Reads??????????????????SQL ordered by Executions?????д?????SQL ordered by Parse Calls???sql?????????????Sql?????????????????????????????????top5????????????????sqlλ???????????sql?????????????????SQL??????????????????????OLTP?????????????????????????????????????????????????top5????г???????????sql????????Latch????????????????????Щsql???????????

????Latch???????????????????Latch????????????????????????????Latch??oracle???????????????????Latch??????????????????????????鱻??????????????У???????????????????????????飬???????????????????Latch???????

??????Latch?????????????????δ??????????????????????????е?sql????????Щ???????????????????Щsql??????????????????????β?????????????鱻????????????????????????

????Statspack???滹?к???????????I/O????????棬???????????

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