Library.Latch.Buffer three key indicators of the percentage of hits
- Library Hit
select round (sum (pinhits) / sum (pins) * 100,2) "Library Hit (%)"
from v $ librarycache;
- Latch Hit
select round ((1-sum (misses) / sum (gets)) * 100,2) "Latch Hit (%)"
from v $ latch;
- Buffer Hit
select round (100 * (1 - (a.value-b.value-nvl (c.value, 0)) / d.value), 2) "Buffer Hit (%)"
from v $ sysstat a, v $ sysstat b, v $ sysstat c, v $ sysstat d
where a.name = 'physical reads'
and b.name = 'physical reads direct'
and c.name = 'physical reads direct (lob)'
and d.name = 'session logical reads';
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