Run poll threads on CPU or network virtual processors

Poll threads can run either on CPU virtual processors or on network virtual processors.

In general, and particularly on a single-processor computer, poll threads run more efficiently on CPU virtual processors. This might not be true, however, on a multiprocessor computer with many remote clients.

The NETTYPE parameter has an optional entry, called vp class, which you can use to specify either CPU or NET, for CPU or network virtual-processor classes, respectively.

If you do not specify a virtual processor class for the interface/protocol combination (poll threads) associated with the DBSERVERNAME variable, the class defaults to CPU. The database server assumes that the interface/protocol combination associated with DBSERVERNAME is the primary interface/protocol combination and that it is the most efficient.

For other interface/protocol combinations, if no vp class is specified, the default is NET.

While the database server is in online mode, you cannot drop a CPU virtual processor that is running a poll or a listen thread.

Important: You must carefully distinguish between poll threads for network connections and poll threads for shared memory connections, which run one per CPU virtual processor. TCP connections must only be in network virtual processors, and you must only have the minimum required to maintain responsiveness. Shared memory connections must only be in CPU virtual processors and run in every CPU virtual processor.

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