Specifying conditions on row retrieval
If a report accesses data from a database or an XML data source, you can specify filter conditions to retrieve a certain set of data from the data source. By filtering at the data source level and retrieving a limited number of rows, you improve performance. The larger the number of rows a data set returns, the more memory and resources BIRT uses to store and process the rows. This section covers some typical ways to filter data in a database and XML data source.