Using enhanced record selection formulas

The most important thing you can do to speed up report processing is to limit the amount of data that is returned from the database. Your primary tool for doing this is the record selection formula.

Crystal Reports analyzes your record selection formula and generates an SQL query from it. This SQL query is then processed by the database, which sends the resulting records back to Crystal Reports. Crystal Reports then evaluates the record selection formula locally for each of the records retrieved from the database, thereby calculating the set of records used to generate the report.

Unnecessary records are eliminated at two stages: at the database with the SQL query and within Crystal Reports by the record selection formula. For speed, you want as many records as possible to be eliminated in the first stage. By designing your record selection formula effectively, you can off-load much of the processing to the database server, thus eliminating unnecessary records before returning them to Crystal Reports. This is commonly called "pushing record selection down to the database server."

For a brief demonstration of how pushing record selection down to the database server can improve performance, see Pushing down record selection—an example.

This section offers several tips to ensuring that your record selection formulas can be pushed down to the database server:



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