Of course, to use these features properly you must
be aware of the access patterns for the various objects used by your application.
Oracle Database 10g simplifed management of buffer cache size by introducing a new
dynamic parameter, DB_CACHE_SIZE. This parameter can be used to specify cache
memory size and replaced the DB_BLOCK_BUFFERS parameter present in previous
Oracle releases. DB_CACHE_SIZE is automatically sized if MEMORY_TARGET or
SGA_TARGET is set. Other initialization parameters include DB_KEEP_CACHE_
SIZE and DB_RECYCLE_CACHE_SIZE and these must be manually sized if used.
Shared pool
The shared pool caches various constructs that can be shared among users. For
example, SQL queries and query fragments issued by users and results are cached so
they can be reused if the same statement is submitted again. PL/SQL functions are
also loaded into the shared pool for execution and the functions and results are
cached, again using an LRU algorithm. As of Oracle Database 11g, a PL/SQL function
can be marked in such a way that its result will be cached to allow lookup rather
than recalculation when it is called again using the same parameters.
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