About summary tables
A summary table presents aggregate data information in a report, providing users with a concise view of the data. A summary table helps improve response time, reduce network traffic, and enables customers to view the data they need in a format that is easily understood. The summary table feature in BIRT Studio enables report users to display only aggregate data from data sets that contain a large volume of data. The aggregate calculation occurs at the data source level, which enables users to quickly view summary information at a glance.
When a report design presents all detail rows of a data set, with or without aggregate data, the table is called a detail table. In a report containing grouped data, by hiding the details for a group, you can provide the user with a simplified view of the aggregate data. Using a summary table to achieve the same result improves performance, and reduces the load on the server, when dealing with large volumes of data.
For example, from a data source that contains two fields—Order Status and Amount—using a summary table, the user can view the total amount for each status. In an ordinary report design, BIRT Studio retrieves the sales for each status and calculates the sum of the Amount. When you use a summary table, BIRT Studio calculates the sum of the Amount field at the data source level, and presents the corresponding values in the report design. You can use a template containing one or more data sets, an information object, or a data object to create a summary table. This section describes how you can use BIRT Studio to create and modify a summary table.

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