Oracle Tips by Burleson Consulting
When to trigger a dynamic
When your scripts detect a condition where a RAM memory region is
overstressed, you are faced with a choice about which region will
shrink to provide the RAM for the over-stressed area. Table 7-2
below provides the threshold condition for triggering a dynamic
Library cache misses
Data buffer cache
Hit ratio < 90%
Hit ratio > 95%
high multi-pass executions
100% optimal executions
Table 2: Threshold conditions for dynamic RAM re-allocation
In practice, the choice of which area to reduce is size is a choice
between the shared pool and the PGA aggregate memory. This is
because the shared pool is almost always a small region when
compared to the regions for the data buffers and PGA session memory.
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