Valid from List & Label 15Since List & Label 20 filtering on the database level is possible. The datafilter dialog displays the speed of the defined filter in form of a flash icon.
For performance reasons, we strongly suggest to do any filtering before passing the data source to List & Label and starting the print out. That way, you can make sure that only the data that's actually required is requested from the data source. If you put the filtering into the report, all records would be fetched and then thrown away if the record doesn't match the filter which is usually desireable for rather small reports only.
When dealing with huge amounts of data, we discourage the use of .NET DataSets. These are in-memory objects that don't scale very well. You'd rather use a DbCommandSetDataProvider which uses fast, forward only IDataReader objects to access the data. This DataProvider scales very well with huge amounts of data as well. Avoid using the TotalPages$() function in your report in this case, as otherwise the report has to be built up in memory first in order to calculate the total number of pages.