A data set can provide more information than your report needs. You can select specific data rows to use in a report by using a filter. Filtering data helps you work effectively with large amounts of data to find the pieces of information that answer specific business questions, such as which sales representatives generated the top 10 sales accounts, which products generated the highest profit in the last quarter, which customers have not made a purchase in the past 90 days, and so on. Filtering data in a BIRT design can measurably reduce the load on the database server, improving processing speed, because it reduces the number of data rows retrieved when the BIRT design is run.

Report Studio supports the use of static filters and dynamic filters. Use a static filter to define a filter condition at report design time. The data displayed in the BIRT design depends on the filter condition specified. Use a dynamic filter to prompt a user to specify values at run time. The data that appears in the BIRT design depends on the values the user specifies when generating a BIRT design.

When you use filters in a BIRT design, Report Studio typically evaluates the filter condition against the rows of data previewed in the BIRT design, 50 rows by default. Increase this number to the maximum value of 200 rows when creating filter conditions. If you use the default preview value of 50 data rows to test a filter condition, Report Studio can fail to return any data that matches the filter you define. Run the report in the viewer to view the actual data, and verify that the result is what you expect.