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[vj.jain]

Oracle 11g has introduced a new background process to support server-side connection pooling called Database Resident Connection Pooling (DRCP). With DRCP, different application processes can share sessions on the same machine and also across a multitude of machines. This new feature greatly increases the scalability of applications that cannot be deployed as multithreaded, such as PHP applications. DRCP is also useful to multi-threaded applications that frequently maintain idle connections.

Database Resident Connection Pooling provides a connection pool within the database server to support situations where an application requires a database connection for a short amount of time before releasing the connection. DRCP works by creating a pool of dedicated servers which consist of a server foreground and a database session combined; a model that is referred to as “pooled” servers.

The pooled servers are managed within the database by a process called the “connection broker”. Upon a client request, the connection broker hands-off the client to an available pooled server. If no pooled servers are available, it creates one. If the pool has reached its defined maximum, the client request is placed on a queue until a pooled server is available. The client communicates directly with the assigned pooled server, which essentially behaves as a dedicated server, until the client releases it, at which time the pooled server is returned to the connection broker.



For more information about DRCP (Server-side connection pooling), 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