"Library Hit %" Statistic Displays Negative Value in AWR Report (Doc ID 1604214.1)
現(xiàn)象為：
Instance Efficiency Percentages (Target 100%) section contains a negative Percentage value for the "Library Hit %" statistic in an AWR report.
報(bào)告中的Efficiency Percentages部分Library Hit %數(shù)據(jù)為負(fù)值百分比
原因?yàn)椋?br>The variable used to store this statistic is sized at 2^32. If a number is so large that it exceeds this then it 'wraps' and can display negative numbers. If figures in a prior snapshot are extremely high and then extremely low in the next, then it is possible to see negative values. This can be particularly apparent if the database was shutdown in the snapshots that are being compared. If the database was not re-started, then you can assume that any negative values are at least 2^32.
用于存儲(chǔ)此統(tǒng)計(jì)信息的變量大小為2^32。如果某個(gè)數(shù)字太大以至于超過此值，則它會(huì)“換行”并顯示負(fù)數(shù)。如果前一張快照中的數(shù)字非常高，然后下一張快照的數(shù)字非常低，則有可能看到負(fù)值。如果正在比較的快照中關(guān)閉了數(shù)據(jù)庫，這一點(diǎn)尤其明顯。如果數(shù)據(jù)庫未重新啟動(dòng)，則可以假設(shè)任何負(fù)值至少為2^32。
目前暫無處理方法，如果不同時(shí)期的負(fù)載差異很大，請(qǐng)盡量不要比較這些快照。