Note that this is
true for all statistics used for performance tuning. Ideally, the value of ???redo buffer
allocation retries??? should be close to 0. If you observe the value rising during the
monitoring period, you would increase the size of the redo log buffer by resetting the
LOG_BUFFER initialization parameter.
Query results caching
One of the most significant performance features in Oracle Database 11g can be used
to help improve the performance of repeated queries. Oracle caches database and
index blocks, eliminating the need to perform resource-intensive disk reads. Oracle
caches SQL plans, eliminating the need to reparse and optimize queries. But prior to
Oracle Database 11g, a cached SQL plan would still have to execute and assemble a
result set.
The new feature allows Oracle Database 11g to cache the completed result set in the
shared pool. This new functionality means that a repeated query requesting the same
result set can simply take that result set completely from memory. Since the result
sets have to be the same for this feature to work, the query results cache has the biggest
impact on situations like web page serving, where the same page is being
retrieved repeatedly.
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