User`s guide

• When a scheduled report is processed, all date and time formulas are evaluated by the Job Server
in order to generate the report instance. When you simply view the resultant report instance, none
of the formulas are re-evaluated.
• When you view a cached report page, none of the date functions are re-evaluated, because the
records have already been read and the page has already been formatted.
• If you use date and/or time functions in a report's selection formula, the report's data is dependent
upon the return values of those formulas. Consequently, when you view a report instance at a later
date, the function may cause the report data to be updated from the database.
• To ensure that date and time functions return the values that you expect, you can force the evaluation
time through the use of the WhileReadingRecords and WhilePrintingRecords functions.
For more information, see the "Functions" and "Report Processing Model" sections of the Crystal
Reports Online Help.
6.3 Making the right design choices
This section offers design options and considerations that will help improve the performance of your
reports. The topics covered range from basic suggestions, such as updating reports created in older
versions of Crystal Reports to the latest file format, to more involved decisions, such as whether to use
live or saved data, and how to use subreports efficiently.
When designing your reports, and especially when designing reports for the Web, you should allow
report users to drive the data they see. In other words, display summarized information, so each user
can navigate the report quickly and then drill down to access additional data. In this way, web traffic
and response times are minimized, because only the data requested by the user is transferred from
the database server.
These are only a few of the benefits of designing user-driven reports:
• Report users gain interactive control over the type and quantity of information they view over the
Web.
• Data transfer and network traffic decrease, because only the information requested by users is
returned from the database server.
• When users need real-time reporting of live data over the Web, user-oriented reports respond quickly
and communicate efficiently with the database server.
• Reports become more useful, because each user customizes the report's contents, thereby creating
a reporting solution specific to his or her particular decision-making problem.
6.3.1 Using faster report formats
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Designing Optimized Web Reports