Resolution:
Description:
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Will topic consumers with message selectors have the same performance impact as queue consumers with message selectors?

Environment:
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ALL

Resolution

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If messages are pending on a queue and you start a message consumer with a selector, the server will have to potentially evaluate all pending messages to see if the consumer can receive them. However, for a topic subscriber/durable, the evaluation is done only once: when the message comes in. The selector evaluation is done in the server and it is then decided to which message consumers the message is assigned. Once this is done, no further evaluation is needed. In other words, starting a topic subscriber/durable with a selector does not cause a performance impact since there is no need to evaluate messages already pending on the topic. Selectors can be expensive for *queue* consumers only.

Performance impact when topic and queue consumers use message selectors.