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[vj.jain]

Oracle 11g introduces a number of features to expand the use of memory caching in order to improve query performance and decrease the overall memory requirements of queries and applications. In addition to the features that support server-side caching (discussed in Chapter 6), there is also a new feature to support a client-side result cache that allows OCI clients to fetch result sets stored in process memory instead of requiring access to the server’s memory. The “Client Result Cache” is enabled and configured at the database level and available to all OCI-based clients.

Using the client’s memory to cache query result sets significantly improves the performance of repetitive queries by OCI-based clients that would otherwise require a cache hit on the server-side. The client cache utilizes per-process memory on the OCI client and its contents can be shared across multiple sessions and threads. When executing repetitive queries, the clients fetch results directly from the client cache rather than having the server execute the query. In certain situations, this will greatly reduce the number of round-trips between the client and the database server, reducing CPU consumption on the server and greatly increasing the response times. Situations that will benefit most from the client cache are queries that use small lookup tables or mostly read-only tables.


For more information about the Client Cache, make sure you get a copy of Oracle 11g New Features Guide by John Garmany, Steve Karam, Lutz Hartmann, V. J. Jain, and Brian Carr http://www.oracle-developer.com/oracle_11g_new_features.html