This image illustrates how the middle tier handles requests for Web pages. The request originates in a user's browser and makes its way across the internet to Oracle Web Cache. Oracle Web Cache requests and receives a page stub that is generated by Portal Services, and then parses the page stub and retrieves additional user and page security metadata. It then requests the content from Portal Services. If no valid cached copy of the page definition exists, then the portal schema in the Oracle Metadata Repository generates a page definition. The content of the page is assembled using cached and generated page and portlet content. Oracle Web Cache returns the final page to the client browser.

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