请各位专家指教:为什么我的Read Hit Ratio -45.316746?
select 1-(sum(decode(name, 'physical reads', value,0))/
(sum(decode(name, 'db block gets', value,0)) +
(sum(decode(name, 'consistent gets', value,0))))) * 100
"Read Hit Ratio"
from v$sysstat;
Read Hit Ratio
--------------
-45.316746
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