LIBRARY CACHE HIT RATIO

July 30, 2012 admin Old but still valuable, Oracle

The Library Cache Hit Ratio reflects the percentage of time an object such as a package, procedure, or function was in memory. The value should be very high and around 99%.
To identify the Library Cache Hit Ratio execute the following:
SELECT SUM(pins-reloads)/SUM(pins)*100 “Library Cache Hit Ratio”
FROM v$librarycache

If any of the hit ratios fall below 75 percent, you should add to the shared_pool_size.

DB CACHE HIT RATIO 32-bit? 64-bit?