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whenever I make a new request in my application it takes to long to respond for the first time and all the subsequent requests are faster. If I do it again after some hours or tomorrow again it takes more time to respond and same subsequent requests respond quickly. I am not sure why this is happening every now and then even though the server is not restarted. I can understand if it is issue of explain plan creation. But the explain plan is created only once for the first time and it should not be slow there after. But I am keep on experiencing periodically even though the server is not restarted.