The Crystal Reports page server is responsible for responding to page requests by processing reports and generating encapsulated page format (EPF) pages.
The key benefit of EPF is that it supports page-on-demand access so only the requested page is returned, instead of the entire report.
This enhances performance and reduces unnecessary network traffic for large reports.
The EPF pages contain formatting information that defines report layout. The page server retrieves data for the report from an instance or directly from the database (depending on the user request and the rights he or she has to the report object).
When retrieving data from the database, the page server automatically disconnects from the database after it fulfils its initial request and if necessary, reconnects to retrieve additional data. This helps conserve database traffic and limit the unnecessary use of database licenses.
The SAP BOBJ - Cache servers and Page Server work closely together. Specifically, the Page Server responds to page requests made by the Cache Server.
The Page Server and Cache Server also interact to ensure cached EPF pages are reused as frequently as possible, and new pages are generated as required. BusinessObjects Enterprise takes advantage of this behavior by ensuring that the majority of report-viewing requests are made to the Cache Server and Page Server.
However, if a user’s default viewer is the DHTML viewer, the report is processed by the Report Application Server (RAS).